Noise attenuation components

ABSTRACT

A reduction device includes a housing defining an input chamber configured to receive exhaust from a power source, an output chamber, an exhaust channel configured to direct the exhaust from the input chamber to the output chamber, and a longitudinal axis. The reduction device also includes a treatment unit disposed in the exhaust channel and along the longitudinal axis. The treatment unit is configured to at least partly remove pollutant species from the exhaust. The reduction device also includes an attenuation component disposed in the housing and radially outward of the treatment unit. The attenuation component is fluidly connected to the exhaust channel, and is configured to attenuate a range of frequencies corresponding to operation of the power source. Additionally, the exhaust channel prohibits exhaust entering the input chamber from exiting the housing without passing through the treatment unit.

TECHNICAL FIELD

The present disclosure relates to noise attenuation systems for internalcombustion engines. More specifically, the present disclosure relates toexhaust treatment systems, and corresponding noise attenuationcomponents that are tunable to attenuate noise in one or more frequencyranges.

BACKGROUND

Internal combustion engines, including diesel engines, gasoline engines,natural gas engines, gaseous fuel-powered engines, and other enginesknown in the art exhaust a complex mixture of air pollutants. These airpollutants are composed of gaseous compounds such as nitrogen oxides(NO_(X)), and solid particulate matter also known as soot. Due toincreased awareness of the environment, exhaust emission standards havebecome more stringent, and the amount of NO_(X) and soot emitted to theatmosphere by an engine may be regulated depending on the type ofengine, size of engine, and/or class of engine.

In order to ensure compliance with the regulation of NO_(X), some enginemanufacturers employ strategies in which the exhaust gas is passedthrough a diesel particulate filter (DPF), an oxidation catalyst, orother aftertreatment devices in order to remove particulates and otherpollutants carried by the exhaust. Additionally or alternatively, aselective catalytic reduction (SCR) process can be employed in which agaseous or liquid reductant, most commonly urea, is injected into theexhaust gas stream and is absorbed onto a substrate. The reductantreacts with NO_(X) in the exhaust gas to form H₂O and N₂. However,passing exhaust gas through a DPF, an SCR device, or otheraftertreatment devices downstream of the internal combustion engine cangenerate a significant level of noise. Accordingly, some noise-sensitivelocations require the use of noise attenuation components, such asmufflers, configured to reduce exhaust-related noise in variousfrequency ranges.

An example system for sound attenuation is described in U.S. PatentApplication No. 2017/0218806 (hereinafter referred to as the '806reference). In general, the '806 reference describes a muffler systemwith three chambers for sound attenuation. Additionally, the '806reference describes a system that includes an input pipe that deliversexhaust gas into the muffler and propagates sound into the internalchamber of the muffler that is configured to attenuate the sound throughinternal geometry to cause destructive interference. Internally, themuffler of the '806 reference describes that the internal structure ofthe muffler may be divided into three chambers that provide attenuationand are in fluid communication with the exhaust as it passes through themuffler.

Although the system described in the '806 reference may be configured toattenuate noise associated with engine exhaust gas, the system is noteasily configurable or “tunable” by the user. For example, the systemdescribed in the '806 reference is not tunable to facilitate theattenuation of particular frequency ranges specific to the engine and/orreduction devices with which it is used. Additionally, due to the largenumber of unique parts included in the system of the '806 reference, useof this system may increase the overall cost and complexity of thereduction device.

Examples of the present disclosure are directed toward overcoming one ormore of the deficiencies noted above.

SUMMARY OF THE INVENTION

Examples of the present disclosure are directed to a reduction devicethat includes a housing, an input chamber, an output chamber, an exhaustchannel, a longitudinal axis, a treatment unit, and an attenuation unit.The housing can include the input chamber configured to receive exhaustfrom a power source, the output chamber downstream of the input chamber,the exhaust channel disposed between the input chamber and the outputchamber, the exhaust channel configured to direct the exhaust from theinput chamber to the output chamber, and the longitudinal axis extendingsubstantially centrally through the housing. Additionally, the treatmentunit can be disposed in the exhaust channel and along the longitudinalaxis, the treatment unit being configured to at least partly removepollutant species from the exhaust as the exhaust passes through theexhaust channel. Further, the attenuation component can be disposed inthe housing and radially outward of the treatment unit, wherein theattenuation component is fluidly connected to the exhaust channel, andis configured to attenuate a range of frequencies corresponding tooperation of the power source at a rated load and the exhaust channelprohibits exhaust entering the input chamber from exiting the housingwithout passing through the treatment unit.

Further examples of the present disclosure are directed to a method thatincludes receiving exhaust at an input chamber of a housing, the inputchamber being in fluid communication with an output chamber of thehousing via an exhaust channel of the housing. Additionally, the methodincludes attenuating, with an attenuation component disposed within thehousing and fluidly connected to the exhaust channel, a range offrequencies associated with the exhaust as the exhaust passes throughthe exhaust channel. Further, the method includes removing, with atleast one of a first treatment unit and a second treatment unit, apollutant species from the exhaust as the exhaust passes through theexhaust channel. It should be noted that the first treatment unit beingdisposed within the exhaust channel, the second treatment unit beingdisposed within the exhaust channel downstream of, and spaced from, thefirst treatment unit, and the attenuation component being disposedradially outward of the first treatment unit and the second treatmentunit. Further the method includes directing the exhaust to exit thehousing via the output chamber, the exhaust channel prohibiting theexhaust from exiting the housing via the output chamber without passingthrough the at least one of the first treatment unit and the secondtreatment unit.

Still further examples of the present disclosure are directed to asystem that includes a power source configured to emit exhaust and areduction device fluidly connected to the power source and configured toreceive the exhaust. For example, the reduction device can include ahousing, an exhaust channel, a plurality of treatment units, and aplurality of attenuation units. In particular, the housing unit candefine an input chamber, an output chamber downstream of the inputchamber, and a longitudinal axis. Additionally, the exhaust channel canfluidly connect the input chamber with the output chamber and thelongitudinal axis of the housing can extend substantially centrallythrough the exhaust channel. Further, the plurality of treatment unitscan be disposed within the exhaust channel, the plurality of treatmentunits being configured to remove pollutant species from the exhaust asthe exhaust passes through the exhaust channel. It should be noted thatthe plurality of attenuation components disposed within the housing andfluidly connected to the exhaust channel, the plurality of attenuationcomponents being configured to attenuate a range of frequenciesassociated with the exhaust passing through the exhaust channel,corresponding to operation of the power source at a rated power load,and being disposed radially outward of the plurality of treatment units.Additionally, a support lattice can be connected to at least one wall ofthe exhaust chamber and supporting the plurality of treatment unitswithin the exhaust channel, wherein the reduction device is configuredsuch that the exhaust received from the power source is prohibited fromexiting the housing without passing through at least one treatment unitof the plurality of treatment units.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary power system, such as a diesel-fueledinternal combustion engine, that outputs exhaust according to examplesof the present disclosure.

FIG. 2 is a radial cross-sectional illustration of a reduction devicethat incorporates sound attenuation components in parallel withtreatment units according to examples of the present disclosure.

FIG. 3 is a longitudinal cross-sectional illustration of a reductiondevice that incorporates sound attenuation components in parallel withtreatment units according to additional examples of the presentdisclosure.

FIG. 4 is a longitudinal cross-sectional illustration of a reductiondevice that incorporates Helmholtz resonators in parallel with treatmentunits to further examples of the present disclosure.

FIG. 5 is a longitudinal cross-sectional illustration of a reductiondevice that incorporates ¼ wavelength resonators in parallel withtreatment units according to other examples of the present disclosure.

FIG. 6 is a longitudinal cross-sectional illustration of a reductiondevice that incorporates Helmholtz resonators and ¼ wavelengthresonators in parallel with treatment units according to still furtherexamples of the present disclosure.

FIG. 7 is a radial cross-sectional illustration of a reduction devicethat incorporates Helmholtz resonators and/or ¼ wavelength resonators inparallel with treatment units according to additional examples of thepresent disclosure.

FIG. 8 is a longitudinal cross-sectional illustration of a configurablereduction device that incorporates sound attenuation components inparallel and in series with treatment units according to still otherexamples of the present disclosure.

FIG. 9 is a longitudinal cross-sectional illustration of alternateconfigurations for a reduction device that incorporates soundattenuation components in parallel with treatment units according toadditional examples of the present disclosure.

FIG. 10 is a radial cross-sectional illustration of a reduction devicethat incorporates sound attenuation components in parallel with multipleexhaust channels according to further examples of the presentdisclosure.

FIG. 11 is a longitudinal cross-sectional illustration of a reductiondevice that incorporates sound attenuation components in parallel withtreatment units and includes an elbow that changes the direction of thelongitudinal axis of the reduction device

DETAILED DESCRIPTION

Systems and techniques described below are directed to reduction devicesthat comprise noise attenuation components (e.g., resonators,attenuation materials, etc.) in addition to catalysts, exhaustprocessing components, and other internal components. As will bedescribed below, example reduction devices of the present disclosure areconfigured to remove pollutants from combustion exhaust gas, and arealso tunable to minimize noise in frequency ranges specific and/orparticular to the engine or other power systems to which they areconnected.

FIG. 1 illustrates an exemplary power system 100. For the purposes ofthis disclosure, the power system 100 is depicted and described as adiesel-fueled, internal combustion engine. However, it is contemplatedthat the power system 100 may embody any other type of combustionengine, such as, for example, a gasoline, a hydrogen, a natural gas, aliquid fuel, or gaseous fuel powered engine. The power system 100 mayinclude an engine block 102 at least partially including a plurality ofcylinders 104, and a plurality of piston assemblies (not shown) disposedwithin the plurality of cylinders 104 to form combustion chambers. It iscontemplated that the power system 100 may include any number ofcombustion chambers and that the combustion chambers may be disposed inan “in-line” configuration, a “V” configuration, or in any otherconventional configuration. In at least one example, the diesel-fueledinternal combustion engine can be a part of a set of generators (e.g., a“gen-set”) that provide power for a facility. Accordingly, while thepower system 100 is depicted as including a single engine block, thepower system 100 can be configured to include a plurality of engineblocks. It should be noted that the power system can be any powergenerating component that utilizes an internal combustion engine such asthe gen-set, a maritime engine, a motor, an industrial system thatutilizes internal combustion, and other related applications.

In some examples, the power system 100 can be a gen-set configured tooutput power for the facility via operation of the plurality ofcylinders 104 at a rated power load that correlates to a number ofrotations per minute (RPM) by the plurality of cylinders 104. Inparticular, the power system 100, depending on the power environmentwhere the power system 100 is installed, can be configured tocontinuously or substantially continuously output the rated power load.The rated power load can be a defined power load that is approximatelyequivalent to a percentage of a maximum power load of the engine block102 (e.g., 60%, 75%, 80%, 90%, etc. of the maximum power output) andapproximately represents the anticipated operation parameters of thepower system 100. Additionally, and based at least on the rated powerload, an exhaust temperature can be determined for the power system 100that is associated with operation of the engine block 102 and theplurality of cylinders 104. It should be noted that in applicationswhere the power system 100 is configured to operate at a variable powerload (e.g., power load is freely adjusted within an operating poweroutput range), the power system 100 can be associated with a range ofcylinder RPMs and a range of exhaust temperatures that are generated bythe power system 100 during operation within the range of the variablepower load. Accordingly, systems that receive exhaust from the powersystem 100 and/or the engine block 102 can be configured to operate atthe rated power load and/or within the range of the variable power load.

Multiple separate sub-system may be included within the power system100. For example, the power system 100 may include an air inductionsystem 106, an exhaust system 108, and a recirculation loop 110. The airinduction system 106 may be configured to direct air, oxidation agents,and/or an air and fuel mixture, into the power system 100 for subsequentcombustion. The exhaust system 108 may exhaust byproducts of thecombustion to the atmosphere. The recirculation loop 110 may beconfigured to direct a portion of the gases from the exhaust system 108back into the air induction system 106 for subsequent combustion.

The air induction system 106 may include multiple components thatcooperate to condition and introduce compressed air into the pluralityof cylinders 104. For example, the air induction system 106 may includean air cooler 112 located downstream of one or more compressors 114. Theone or more compressors 114 may be connected to pressurize inlet airdirected through the air cooler 112. It is contemplated that the airinduction system 106 may include different or additional components thandescribed above such as, for example, a throttle valve, variable valveactuators associated with each cylinder of the plurality of cylinders104, filtering components, compressor bypass components, and other knowncomponents, if desired. It is further contemplated that the one or morecompressors 114 and/or the air cooler 112 may be omitted, if a naturallyaspirated engine is desired.

The exhaust system 108 may include multiple components that conditionand direct exhaust from the plurality of cylinders 104 to theatmosphere. For example, the exhaust system 108 may include an exhaustpassageway 116, one or more turbines 118 driven by the exhaust flowingthrough the exhaust passageway 116, a particulate filter device 120located downstream of the one or more turbines 118, and a reductiondevice 122 fluidly connected downstream of the particulate filter device120. It is contemplated that the exhaust system 108 may includedifferent or additional components than described above such as, forexample, bypass components, an exhaust compression or restriction brake,an attenuation component, additional exhaust treatment devices, andother known components, if desired.

The one or more turbines 118 may be located to receive exhaust leavingthe engine block 102 and/or the plurality of cylinders 104 and may beconnected to the one or more compressors 114 of the air induction system106 by way of a common shaft to form a turbocharger. As the hot exhaustgases exiting the power system 100 move through the turbine(s) 118 andexpand against vanes (not shown) thereof, the turbine(s) 118 may rotateand drive the connected compressor(s) 114 to pressurize inlet air.

The particulate filter device 120 may comprise a particulate filter, andis located downstream of the turbine 118 to remove particulates from theexhaust flow of the power system 100. The particulate filter device 120may include an electrically conductive or non-conductive coarse meshmetal made from a metallic material or porous ceramic honeycomb mediummade from a ceramic material. As the exhaust flows through the medium,particulates may be blocked by and left behind in the medium. Over time,the particulates may build up within the medium and, if unaccounted for,could negatively affect engine performance.

To minimize negative effects on engine performance, the collectedparticulates may be passively and/or actively removed through a processcalled regeneration. When passively regenerated, the particulatesdeposited on the filtering medium may chemically react with a catalyst,for example, a base metal oxide, a molten salt, and/or a precious metalthat is coated on or otherwise included within particulate filter tolower the ignition temperature of the particulates. The particulatefilter device 120 may be closely located downstream of the engine block102 (e.g., immediately downstream of the one or more turbines 118, inone example). In some examples, the temperatures of the exhaust flowentering the particulate filter device 120 may be high enough, incombination with the catalyst, to burn away the trapped particulates.When actively regenerated, heat may be applied to the particulatesdeposited on the filtering medium to elevate the temperature thereof toan ignition threshold. For this purpose, an active regeneration devicemay be located proximal (e.g., upstream of) the particulate filter. Theactive regeneration device may include, for example, a fuel-firedburner, an electric heater, or any other device known in the art. Acombination of passive and active regeneration may be utilized, ifdesired.

The reduction device 122 may receive exhaust from the one or moreturbines 118 and reduce constituents of the exhaust to innocuous gases.In the example shown in FIG. 1 , the reduction device 122 is disposeddownstream of the particulate filter device 120. In other examples, theparticulate filter device 120 may be omitted, and in such examples, asubstrate, mesh, filtering medium, or other component of the reductiondevice 122 may perform the task of physically blocking and/or otherwisecapturing particulates included in the exhaust. In any of the examplesdescribed herein, the reduction device 122 may embody a selectivecatalytic reduction (SCR) device that includes one or more treatmentunits 124. The treatment units 124 may comprise a metal mesh, a ceramichoneycomb medium, and/or any other filtering medium, and in suchexamples, the filtering medium within the treatment units 124 may becoated with a reduction catalyst selected from any of the catalyticcompounds described herein (e.g., a hydrolysis catalyst) to assist withcatalytic reduction. In some examples, a gaseous or liquid reductant maybe sprayed or otherwise advanced into the exhaust upstream of the one ormore treatment units 124. As the reductant is absorbed onto the surfaceof the one or more treatment units 124, the reductant may react withNO_(X) (NO and NO₂) in the exhaust gas to form water (H₂O) and elementalnitrogen (N₂). In some embodiments, the catalytic compound(s) disposedon the one or more treatment units 124 is configured to promote evendistribution and conversion of urea to ammonia (NH₃).

As shown in the enlarged view of FIG. 1 , an example treatment unit 124comprises a filter mesh 130 that a reduction catalyst 132 (e.g., thehydrolysis catalyst described above) is deposited on for the purposes ofSCR catalyzation. In particular, one or more of the treatment units 124are disposed with and/or otherwise supported by a support lattice 128within the reduction device 122. The support lattice 128 comprises oneor more substantially rigid walls that secure and/or otherwise supportthe filter mesh 130 relative to the flow of exhaust therethrough. Morespecifically, the support lattice 128 can include a first wall, and asecond wall that is disposed substantially parallel to the first walland spaced from the first wall at a distance D1. Additionally, thesupport lattice 128 can include a third wall, and a fourth wall that isdisposed substantially parallel to the third wall and spaced from thethird wall at a distance D2. The first wall, the second wall, the thirdwall, and the fourth wall can be connected together, in theconfiguration shown in FIG. 1 , via weld joints, secured via fasteners(e.g., screws, bolts, rivets, etc.), and/or be cast to form the supportlattice 128. While FIG. 1 depicts a square to represent across-sectional area of the treatment units 124, the treatment units 124can take the form of a cylindrical prism, other cuboids, triangularprisms, hexagonal prisms, and/or other three-dimensional (3D) shapes foroptimizing packing within the reduction device 122. Further, the filtermesh 130 can be secured to the four walls of the support lattice 128such that the filter mesh 130 removes various particulates from theexhaust traversing the treatment units 124. The reduction catalyst 132can be deposited on the filter mesh 130 such that the gaseous or liquidreductant sprayed or otherwise advanced into the exhaust absorbs ontothe reduction catalyst 132 and reacts with pollutant species within theexhaust. In any of the examples described here, the number, type, size,shape, location, spacing, and/or other configurations of the filtrationand reduction components within the reduction device 122 can be selectedand/or modified to achieve a desired level of exhaust treatment and/or adesired flowrate of exhaust through the reduction device 122 for thepower system 100.

The reduction device 122 may also be configured to attenuate soundgenerated by the engine block 102, the cylinders 104, the compressor(s)114, the turbine(s) 118, and/or other components of the power system100. In particular, the power system 100 can be located at and/orassociated with a facility that has low ambient sound pressures suchthat the sound generated by the power system 100 is determined toutilize dampening and/or attenuation that is generally not provided bythe reduction device 122. Additionally, utilization of an independentmuffler that is installed subsequent to (e.g., downstream from, inseries with) the reduction device 122 to accomplish sound dampeningand/or attenuation can be undesirable due to the additional expense,space utilization, and other drawbacks associated with such devices. Aswill be described in greater detail below, in some examples, availablevolume within a housing of the reduction device 122 enables integrationof sound attenuation modules. Accordingly, the reduction device 122 canbe configured as a modular system that utilizes attenuation components(e.g., one or more resonators 126, attenuation materials, etc.) andtreatment units 124 to accomplish both sound attenuation (e.g.,dampening) and exhaust treatment for the power system 100. In any of theexamples described here, the number, type, size, shape, location,spacing, and/or other configurations of the attenuation componentswithin the reduction device 122 can be selected and/or modified toachieve a desired level of attenuation and/or to attenuate desiredfrequencies associated with the power system 100.

With continued reference to FIG. 1 , the reduction device 122 includes ahousing 134 (e.g., a cylindrical housing, a rectangular housing, etc.)that substantially encloses a volume of space (e.g., an internal volumeof the housing 134). In any of the examples described herein, the one ormore treatment units 124, as well as the support lattice 128, aredisposed within the housing 134 (e.g., disposed within the internalvolume). The reduction device 122 also includes one or more resonators126 disposed within the housing 134 and configured to attenuate soundgenerated by the power system 100 and/or by the exhaust passing throughvarious components of the power system 100. In particular, the housing134 and other components of the reduction device 122 are configured suchthat exhaust from the power system 100 is directed to pass through thetreatment units 124 prior to exiting the housing 134. For example, thehousing 134 and other components of the reduction device 122 areconfigured such that exhaust entering the housing 134 is prohibited fromexiting the housing 134 without first passing through and/or otherwisetraversing one or more of the treatment units 124. In some examples, theresonators 126 disposed within the housing 134 are fluidly sealedrelative to the flow of exhaust. In such examples, treated and untreatedexhaust is prevented (e.g., due to the fluidly sealed configuration ofthe one or more resonators 126) from passing over or through the one ormore resonators 126 as the exhaust passes through the reduction device122. Alternatively, as will be described in greater detail below, one ormore of the resonators 126 may be exposed to exhaust passing through thereduction device 122. In such examples, however, and regardless of theinteraction between the exhaust and the one or more resonators 126disposed within the housing 134, the housing 134 and other components ofthe reduction device 122 may still be configured such that exhaustentering the housing 134 is prohibited from exiting the housing 134without first passing through and/or otherwise traversing one or more ofthe treatment units 124. Additionally, in any of the examples describedherein, one or more of the resonators 126 can be tuned to targetspecific frequencies and/or ranges of frequencies to broaden the soundattenuation range (e.g., the range of frequencies that can be attenuatedby the reduction device 122 as a whole) of the reduction device 122.Accordingly, a primary exhaust channel of the reduction device 122 canbe occupied by one or more treatment units 124 that treat the exhaust ofthe power system 100 while additional space within the reduction device122 is at least partly occupied by one or more resonators 126.

In some examples, the reduction device 122 is configured such that thehousing 134 is a cylindrical housing and the treatment units 124 arecuboid structures that include the reduction catalyst. Additionally, thecylindrical housing 134 can be configured such that the treatment units124 occupy a cuboid volume within the reduction device 122. Further, thevolume of the cylindrical housing 134 not occupied by the treatmentunits 124 can be utilized to provide sound attenuation for the powersystem 100. Accordingly, the reduction device 122 can be configured totreat exhaust output by the power system 100 while utilizing theavailable volume within the housing 134 to provide sound attenuation forthe power system 100. Further, the available volume in the housing 134that is not occupied by the treatment units 124 can be configured toprovide sufficient sound attenuation over a range of frequencies suchthat an additional muffler device is not required for the power system100. Various example configurations of the reduction device 122, thetreatment units 124, the attenuation components (e.g., resonators 126),and other components of the present disclosure will be described ingreater detail below with respect to FIGS. 2-8 .

FIG. 2 is a radial cross-sectional illustration of a reduction device200 that incorporates sound attenuation components in parallel withtreatment units. In some examples, the reduction device 200 includes ahousing 202, an internal volume 204, an exhaust channel 206, one or moretreatment units 208, a support lattice 210, a first resonator 212, asecond resonator 214, and attenuation material 216.

In some examples, the housing 202 can be radially outward of the othercomponents of the reduction device 200 and can be configured to providestructural support for the internal components (e.g., exhaust channel206, one or more treatment units 208, a support lattice 210, a firstresonator 212, a second resonator 214, and attenuation material 216).While the housing 202 is depicted as being cylindrical, and as having asubstantially circular cross-section, in other examples, the housing 202may be any three-dimensional (3D) shape that exhaust from a power systemcan longitudinally traverse from input to output. For instance, in otherexamples, the housing 202 may be substantially cube-shaped or any other3D shape, and may have a cross-section that is substantially square,substantially rectangular, substantially hexagonal, and/or or any othertwo-dimensional (2D) shape. As such, and since the cross-section of thehousing 202 can have any 2D shape, the terms “radial” and “radially,” asused herein, should not be construed as being applicable only tocomponents, devices, and other items having substantially circularcross-sections. Instead, unless clearly indicated otherwise, the terms“radial” and “radially” refer to directions extending outwardly from acentral axis of the respective item, regardless of the cross-sectionalshape of the item. Similarly, unless clearly indicated otherwise, theterms “longitudinal” and “longitudinally” refer to directions extendingsubstantially parallel to the central axis of the respective item,regardless of the shape of the item. For example, the housing 202includes an external surface 202 a that is radially outward of an innersurface 202 b, and the internal components of the reduction device 200can be secured by and/or affixed to the inner surface 202 b of thehousing 202. Further, the housing 202 defines the internal volume 204for the treatment of power system exhaust and/or for attenuating soundsfrom the power system.

In some examples, the exhaust channel 206 extends longitudinally alongand/or within at least a portion of the internal volume 204 of thehousing 202. In such examples, the exhaust channel 206 is, at least inpart, in fluid communication with an input of the reduction device 200and an output of the reduction device 200. Additionally, the one or moretreatment units 208 and the support lattice 210 can be disposed withinthe exhaust channel 206 and supported at least in part by the exhaustchannel 206. Further, the exhaust channel 206 can be configured suchthat exhaust entering the reduction device 200 travels through theexhaust channel 206 before exiting the reduction device 200. In at leastone example, the exhaust channel 206 forms a substantially fluid tightseal 222 with the inner surface 202 b of the housing 202 such that theexhaust is prevented from bypassing the exhaust channel 206. Similarly,in at least one additional example, the exhaust channel 206 forms thesubstantially fluid tight seal 222 with one or more of the firstresonator 212, the second resonator 214, the one or more additionalresonators 218 and/or the housing 202. Accordingly, and independent ofthe specific configuration of the exhaust channel 206, the input andoutput of the reduction device 200 are in fluid communication with theexhaust channel 206 and the exhaust channel 206 can be configured toprevent untreated exhaust from traversing the reduction device 200 fromthe input to the output.

In some additional examples of the exhaust channel 206, the input andthe output of the reduction device 200 are in fluid communication andenable exhaust to traverse the reduction device 200. For example, theinput and the output of the reduction device 200 can be disposed onopposite longitudinal ends of the housing 202. Additionally, the inputand the output of the reduction device can be disposed on a firstlongitudinal surface and a second longitudinal surface (e.g., flatsurfaces located on either end of the housing 202 that are perpendicularto the central, longitudinal axis of the reduction device 200) of thehousing 202. Alternatively, or in addition, the input and the output ofthe reduction device can be disposed on a radial surface (e.g., thesurface of the reduction device 200 that is at radius R1 from thelongitudinal axis) of the reduction device 200.

In some further embodiments of the exhaust channel 206, the exhaustchannel 206 includes a first wall 206 a, a second wall 206 b, a thirdwall 206 c, and a fourth wall 206 d. In particular, the first wall 206 acan be substantially parallel to the third wall 206 c and separated by avertical distance such that the treatment units 208 are disposed betweenthe first wall 206 a and the third wall 206 c. Similarly, the secondwall 206 b can be substantially parallel to the fourth wall 206 d andseparated by a horizontal distance such that the treatment units 208 aredisposed between the second wall 206 b and the fourth wall 206 d.Additionally, the first wall 206 a, the second wall 206 b, the thirdwall 206 c, and/or the fourth wall 206 d can be joined to form theexhaust channel 206. For example, the exhaust channel 206 can be formedfrom the first wall 206 a, the second wall 206 b, the third wall 206 c,and/or the fourth wall 206 d via weld joints, fasteners (e.g., screws,bolts, rivets, etc.), and/or casting the exhaust channel 206. Further,the first wall 206 a, the second wall 206 b, the third wall 206 c,and/or the fourth wall 206 d can be joined together to form asubstantially fluid tight channel. In some additional examples, theexhaust channel 206 can include the support lattice 210 comprised ofindividual lattice legs (e.g., lattice leg 210 a) that extend between atleast two of the first wall 206 a, the second wall 206 b, the third wall206 c, and/or the fourth wall 206 d and are joined (e.g., joined atapproximately 90 degrees/a right angle) to form individual compartmentswhere the treatment units 208 such that the support lattice includesindividual positions where the treatment units 208 are installed.

In some examples, the one or more treatment units 208 can be locatedwithin the exhaust channel 206 to treat exhaust traversing the reductiondevice 200. In particular, the one or more treatment units 208 can bedisposed within the exhaust channel 206 such that substantially allexhaust that enters the reduction device passes through at least one ofthe treatment units 208. Additionally, the support lattice 210 can beconfigured to secure the treatment units 208 within the exhaust channel206. For example, the support lattice 210 can include bars, plates,and/or other structures that are welded, fastened, and/or otherwisejoined to form a matrix in which the one or more treatment units 208 aredisposed. Additionally, the one or more treatment units 208 can besecured within the support lattice via compressive force (e.g., thesupport lattice 210 is formed such that pairs of lattice legs aresecured to apply compressive force to the treatment units 208 andprevent dislocation), fasteners, welds, and/or other components.Further, individual lattice legs of the support lattice 210 can form asubstantially fluid tight seal 224, in combination with a treatment unitwall 208 a of the treatment units 208, with the inner surface of theexhaust channel 206. More specifically, a lattice leg 210 a of thesupport lattice 210 and the treatment unit wall 208 a of a singletreatment unit 208 can be in contact with a first seal surface 224 a ofthe substantially fluid tight seal 224. Similarly, a second seal surface224 b of the substantially fluid tight seal 224 can be in contact withthe exhaust channel 206 (e.g., the first wall 206 a, the second wall 206b, the third wall 206 c, the fourth wall 206 d, etc.). Accordingly, theone or more treatment units 208 and the support lattice 210 can beplaced within the exhaust channel 206 to convert and/or capturepollutant species within the exhaust such that gaseous species exitingthe reduction device 200 can be output to atmosphere and preventuntreated exhaust from bypassing the one or more treatment units 208. Inat least one example, the distance D can be the thickness of the latticelegs between individual treatment units of the treatment units 208.Additionally, the distance D can be minimized such that the ratio ofactive cross-sectional area (e.g., the surface area of treatment units208 within the exhaust channel 206 that is exposed to the flow ofexhaust through the reduction device) to total cross-sectional area(e.g., the area of the exhaust channel 206) is maximized and the surfacearea of the support lattice 210 is minimized.

In some examples, the one or more treatment units 208 can include atreatment unit housing comprised of a first wall (e.g., the treatmentunit wall 208 a), a second wall substantially parallel to the firstwall, a third wall, and a fourth wall substantially parallel to thethird wall, the first wall and the second wall being connected to thethird wall and the fourth wall at substantially right angles.Additionally, the one or more treatment units 208 can include asubstrate disposed within the treatment unit housing, the substrateformed from one of a metallic material and a ceramic material, and beingconfigured to remove particulates from the exhaust as the exhaust passesthrough the treatment unit. The substrate may be configured as a filtermesh, a filtering medium, or other component that performs the task ofphysically blocking and/or otherwise capturing particulates included inthe exhaust. Further, the substrate can include a reduction catalystsuch that the gaseous or liquid reductant sprayed or otherwise advancedinto the exhaust absorbs onto the reduction catalyst and reacts withpollutant species within the exhaust

In some examples, sound attenuation devices and/or components can beinstalled within the housing 202 and outside of the exhaust channel 206such that internal volume 204 of the reduction device 200 that wouldtypically remain empty around the exhaust channel 206 can be utilized toassist with sound attenuation. In particular, the first resonator 212and the second resonator 214 can be selected from various resonatorsthat are configured to attenuate sound generated by a power systemassociated with the reduction device 200 (e.g., power system 100). Forexample, the first resonator 212 and the second resonator 214 can beselected from Helmholtz resonators, ¼ wavelength resonators, and/orother resonators that can target a sound frequency or a range of soundfrequencies. Additionally, the Helmholtz resonators, the ¼ wavelengthresonators, and/or the other resonators can be configured as passiveresonators (e.g., resonators that attenuate a set range of frequencies)or semi-active resonators (e.g., resonators that attenuate a range offrequencies that is determined by a modifiable volume within theresonator). In at least one embodiment, the reduction device can alsoinclude an active resonator that generates an opposite phase sound wavethat attenuates the soundwaves generated by the power system. Forexample, where a sound wave traversing the reduction device has a trough(e.g., low pressure zone) the active resonator can generate a pressurepeak and where the sound wave has a peak the active resonator cangenerate a trough such that the overall pressure exiting the reductiondevice 200 is at a constant pressure. Accordingly, the first resonator212 and the second resonator 214 can be selected from various resonatortypes and configurations to attenuate sound from the associated powersystem.

In some additional examples, the first resonator 212 can be selectedfrom a Helmholtz resonator, a ¼ wavelength resonator, or another type ofresonator to attenuate sounds within the reduction device 200. Inparticular, the first resonator 212 can be configured to occupy aportion of the internal volume 204 between the housing 202 and theexhaust channel 206. Additionally, the first resonator 212 can beconfigured to form the substantially fluid tight seal 222 in combinationwith the housing 202 and the exhaust channel 206 such that exhaustentering the reduction device 200 is prevented from bypassing thetreatment units 208 via the first resonator 212. Further, the firstresonator 212 can be exposed to the input of the reduction device 200,the output of the reduction device 200, or to the intra-treatment unitvolumes between different radial layers of the treatment units 208 (notillustrated by FIG. 2 ). Accordingly, the first resonator 212 can beconfigured such that the gas within the first resonator 212 issubstantially similar to the gas within the portion of the reductiondevice 200 that the first resonator 212 is exposed to. Morespecifically, the first resonator 212 can encompass a volume of gas thatcan enter and exit the first resonator 212 via a resonator opening(e.g., an opening for the first resonator corresponding to resonatoropening 220 of the additional resonators 218). As will be discussed ingreater detail by FIG. 4 , the first resonator 212 (and other resonatorsassociated with the reduction device 200) can be configured to be influid communication with a portion of the reduction device 200 andisolated from other portions of the reduction device 200 to preventexhaust from bypassing the treatment units 208. For example, the firstresonator 212 can be in fluid communication with the opening of thereduction device 200 and fluidly isolated from the output of thereduction device 200 such that exhaust that enters the first resonator212 via the opening and exits the first resonator back into the volumeof exhaust associated with the opening.

Similarly, the second resonator 214 and additional resonators 218 can beselected from a Helmholtz resonator, a ¼ wavelength resonator, oranother type of resonator to attenuate sounds within the reductiondevice 200. In particular, the second resonator 214 and/or theadditional resonators 218 can be configured to occupy a portion of thevolume between the exterior housing 202 and the exhaust channel 206.Additionally, the second resonator 214 and/or the additional resonators218 can be configured to form the substantially fluid tight seal 222 incombination with the exterior housing 202 and the exhaust channel 206,in a manner similar to the first resonator 212, such that exhaustentering the reduction device 200 is prevented from bypassing thetreatment units 208 via the resonators. As illustrated by FIG. 2 , oneof the additional resonators 218 can be configured such that a resonatoropening 220 (e.g., an opening for a Helmholtz resonator) is exposed tothe volume of space that serves as the input for the reduction device200. Further, the second resonator 214 and/or the additional resonators218 can be exposed to the same portion of the reduction device 200 asthe first resonator 212. Alternatively, or in addition, the secondresonator 214 and/or the additional resonators 218 can be exposed todifferent portions of the reduction device 200 as the first resonator212 and the other resonators of the reduction device 200. Accordingly,the first resonator 212, the second resonator 214, and/or the additionalresonators 218 can provide sound attenuation via exposure to variousportions of the reduction device 200.

In some examples, the first resonator 212, the second resonator 214,and/or the additional resonators 218 can be tuned, selected, and/orotherwise configured based on the audio characteristics of the soundoutput by an associated power system. In particular, the audio profileof the sound output by the associated power system can be determinedbased at least on operating characteristics of the power system. Forexample, the power system can be comprised of a number of cylinderswithin an engine block, a temperature of the exhaust output by the powersystem, and an RPM of the power system while operating. Additionally,the power system can be associated with a rated load that includes theanticipated steady state operation characteristics. More specifically,the rated load can be associated with a temperature of the exhaust andan RPM of the power system during long term operation that experienceslimited fluctuation. Further, the rated load can be associated with asteady state operation of the power source, wherein the steady stateoperation of an associated power system is defined by a substantiallyconstant rotations per minute (RPM) of a generator or engine within thepower system, a substantially constant power output of the generator,and a substantially constant temperature of the flow of exhaust.Accordingly, the first resonator 212, the second resonator 214, and/orthe additional resonators 218 can be configured to attenuate frequenciesgenerated by the power system while the power system is operating at therated load. It should be noted that by tuning the first resonator 212,the second resonator 214, and/or the additional resonators 218 to thefrequencies output by the power system at the rated load can enable moreefficient attenuation and greater attenuation of the frequencies than abroader system of resonators.

In some additional examples, the first resonator 212, the secondresonator 214, and/or the additional resonators 218 can be configuredbased on the audio characteristics of the sound output by an associatedpower system. In particular, the audio profile of the sound output bythe associated power system can be determined based at least onoperating characteristics of the power system. For example, the powersystem can be comprised of a number of cylinders within an engine block,a temperature of the exhaust output by the power system, and an RPM ofthe power system while substantially satisfying a power demand ofassociated systems (e.g., manufacturing facility systems, computationalsystems, marine systems, etc.). Additionally, the power system can beassociated with an operating range that substantially encompassespotential power output of the power system during use. The operation ofthe power system can include variable operating characteristics thatvary as power demands of the associated systems change. Accordingly, thefirst resonator 212, the second resonator 214, and/or the additionalresonators 218 can be tuned to attenuate a range of frequencies suchthat sufficient attenuation is provided across the operating range ofthe power system. It should be noted that individual resonators of thefirst resonator 212, the second resonator 214, and/or the additionalresonators 218 may be configured to provide increased attenuation ofsound frequencies output by the power system during a sub-range of theoperating range compared to the other resonators within the reductiondevice 200. Alternatively, or in addition, the first resonator 212, thesecond resonator 214, and/or the additional resonators 218 may beconfigured to provide substantially equivalent or proportionalattenuation for frequencies output by the power system duringsubstantially all of the operating range. In at least one example, asub-range of the operating range may be identified as a primaryoperating range for the power system that is associated with operatingcharacteristics that are more likely to occur compared to operatingcharacteristics of other portions of the operating range. Accordingly,the first resonator 212, the second resonator 214, and/or the additionalresonators 218 can be configured such that increased attenuation isprovided for frequencies associated with the primary operating range.

In some further examples, and as illustrated by the second resonator214, a resonator that is tuned to attenuate a specific frequency and/ora range of frequencies may not fully occupy a volume 226 between thehousing 202 and the exhaust channel 206 of the reduction device 200. Inparticular, the second resonator 214 can be configured such thatadditional volume between the housing 202 and the exhaust channel 206can be occupied by attenuation materials 216 in addition to the secondresonator 214. It should be noted that while the second resonator 214may occupy a portion of the volume 226 between the housing 202 and theexhaust channel 206, a sealing plate (not illustrated) can be installedsuch that an input chamber, an output chamber, and/or theintra-treatment unit volume(s) are fluidly isolated and that exhaustthat enters the second resonator 214 and/or the volume 226 is preventedfrom bypassing the treatment units 208. More specifically, sealingplates may be installed such that gaseous species from the input, theoutput, and the treatment volume of the reduction device 200 areprevented from mixing. Alternatively, or in addition, the volume 226between the housing 202 and the exhaust channel 206 can be occupied byan additional resonator 218 and/or additional components associated withresonators of the reduction device 200 (e.g., actuators, pistons,motors, etc. for adjusting the configuration of the resonators) inaddition to the second resonator 214. In at least one example, theattenuation material 216 can be utilized to occupy a portion of thevolume 226 between the housing 202 and the exhaust channel 206 such thatthe attenuation materials 216 provided vibration dampening,supplementary attenuation, and other related benefits.

It should be noted that “tuning” the various resonators of the reductiondevice 200 (and other reduction devices discussed herein), refers tomodifying the opening, volume, depth, mass, and other variablesassociated with the resonators to adjust the frequency and/or range offrequencies that are attenuated by the resonators. In its most basicform, the resonant frequency of a rigid cavity can be defined as:

$f = {\frac{v}{2\pi}\sqrt{\frac{A}{V_{0}L_{eq}}}}$It should be noted that f is the resonant frequency of the cavity, v isthe velocity of the sound wave, A is the cross-sectional area of theneck/opening of the cavity, V₀ is the volume of the cavity, and L_(eq)is the adjusted length of the neck/opening of the cavity. The aboveequation illustrates the baseline principles that can be utilized tomodify the frequency and/or the range of frequencies attenuated by thevarious resonators (e.g., the first resonator 212, the second resonator214, the additional resonators 218, etc.). By modifying the volume ofthe resonators, the area of the opening, the effective neck length, andother variables, the targeted frequencies of the various resonators canbe tuned to sound output by the power system associated with thereduction device 200. Additionally, the type of resonator can beselected based on the sound output by the power system as some types ofresonators (e.g., Helmholtz resonators, ¼ wavelength resonators, etc.)can provide greater levels of attenuation, broader ranges of frequenciesattenuated, and/or other tradeoffs that enable optimization of theattenuation provide by the reduction device 200 to the associated powersystem. Further, the attenuation provided by the resonator can beconfigured based on the associated power system at the time ofmanufacturing such that the reduction device is paired with the powersystem or the various resonators can be removed, replaced, and/orreconfigured (e.g., semi-active resonators) by a user that is modifyingthe attenuation provided for the associated power system. Accordingly,the resonators can be substantially permanent fixtures within thereduction device 200 or modular components that can be removed,replaced, and/or adjusted to provide appropriate attenuation for avariety of systems/a system with variable operation.

In some examples, at least one of the resonators can be a Helmholtzresonator that is configured to attenuate a specific frequency and/or arange of frequencies. In particular, the Helmholtz resonator can beconfigured to attenuate a range of frequencies (or frequency) defined atleast in part on a radius R2 (which defines the cross-sectional area ofthe neck) of the opening for the resonator, the volume of the resonator,and other qualities of the resonator (e.g., masses associated with theresonator, the pressure within the resonator, length of a neck of theresonator, etc.). The radius R2 can extend from a central longitudinalaxis of the internal volume 204 (e.g., a substantially spherical volume,a substantially cylindrical volume, a substantially cuboid volume, etc.)of the Helmholtz resonator and be formed by a substantially cylindricalwall that extends from and/or into the Helmholtz resonator.Additionally, the radius R2 extends from the longitudinal axis to theinternal surface of the substantially cylindrical wall. Accordingly, theradius R2 and the volume of the resonator can be altered to determinethe frequencies (or frequency) that is attenuated by the resonator.Further, the Helmholtz resonator can include a modifiable volume suchthat the frequency and/or range of frequencies attenuated by theHelmholtz resonator can be adjusted in situ (e.g., semi-activeresonator) or by a user during configuration of the reduction device200.

As noted above, the input and output of the reduction device 200 are influid communication with the exhaust channel 206 such that exhaustentering the reduction device 200 passes through both the exhaustchannel 206 and the one or more treatment units 208. For example, thesubstantially fluid tight seal 222 can be formed between the exhaustchannel 206 and the first resonator 212, the second resonator 214,and/or the additional resonators 218 such that exhaust entering thehousing 202 is substantially prohibited from bypassing the treatmentunits 208 before exiting the housing 202.

FIG. 3 is a longitudinal cross-sectional illustration of a reductiondevice 300 that incorporates sound attenuation components in parallelwith treatment units. In some examples, the reduction device 300 caninclude a housing 302, an input channel 304, one or more treatment units306 (e.g., treatment unit 306 a through treatment unit 306 l), one ormore resonators 308, and an output channel 310. Additionally, thereduction device 300 can include an input chamber 312 that is positionedlongitudinally upstream of the treatment units 306, one or moreintra-treatment unit volumes (e.g., a first intra-treatment unit volume314 through a third intra-treatment unit volume 318), and an outputchamber 320 that is positioned longitudinally downstream of thetreatment units 306. It should be noted that the reduction device 300can include a housing that substantially similar to that described abovewith respect to FIG. 2 . Further, the treatment units 306 a-306 l can beconfigured in radial layers include a first radial layer 322 (comprisingtreatment units 306 a-306 c), a second radial layer 324 (comprisingtreatment units 306 d-306 f), a third radial layer 326 (comprisingtreatment units 306 g-306 i), and a fourth radial layer 328 (e.g., afourth radial layer 328 comprised of treatment units 306 j-306 l).

In some examples, the input channel 304 can be configured to receiveexhaust output by an associated power system (e.g., power system 100).In particular, the input channel 304 can be fluidly connected to theassociated power system such that exhaust from the power system isdirected to the input channel 304. Alternatively, or in addition, theinput channel 304 can be fluidly connected to a plurality of associatedpower systems such that exhaust is collected from the plurality of powersystems and provided to the reduction device via the input channel.Accordingly, the input channel can be a pipe, a tube, and/or othersubstantially hollow portion of the housing that is configured toreceive exhaust from an associated power system and direct the exhaustto the input chamber 312. The input channel can be in fluidcommunication with the treatment units 306 of the reduction device 300and the resonators 308 that attenuate sound frequencies within thereduction device 300.

Additionally, the input channel 304 can be fluidly connected to an inputchamber 312 that precedes the treatment units 306 and the resonators308. In particular, the input chamber 312 may be in fluid communicationwith one or more of the resonators 308 and/or the treatment units 306.Additionally, the resonators 308 in fluid communication with the inputchamber 312 can be sealed such that exhaust that enters the resonator(s)308 is prevented from bypassing the treatment units 306. Further, thetreatment units 306 can be porous such that exhaust arriving in theinput chamber 312 is forced through the treatment units before enteringthe first intra-treatment unit volume 314. It should be noted that theinput chamber 312 can be defined by the housing 302, the input channel304, and the resonators 308 such that exhaust is permitted to enter theinput chamber 312 via the input channel 304 and exit the input chamber312 via the treatment units 306.

It should be noted that the input chamber 312 is a volume of space thatis encompassed by the housing 302 such that exhaust enters the inputchamber 312 from the input channel 304, exhaust exits the input chamber312 into a first radial layer 322 (comprised of treatment unit 306 athrough treatment unit 306 c), and the input chamber 312 may be in fluidcommunication with adjacent resonators (e.g., resonator 308 a andresonator 308 b). However, it should be noted that the resonator 308 aand the resonator 308 b can be optionally in fluid communication withthe input chamber 312 or the first intra-treatment unit volume 314.Additionally, the input chamber 312 can be radially enclosed by aportion of the housing 302 (e.g. a conical portion of the housing 302).In at least one example, the input chamber 312 can be radially enclosedby a conical portion of the housing 302 that expands from a first radiusR3 measured from the longitudinal axis of the reduction device 300 to afirst interior wall of the housing 302 at the input channel 304 to asecond radius R4 measured from the longitudinal axis of the reductiondevice 300 to a second interior wall of the housing 302 enclosing thetreatment units 306 and the resonators 308. Further, the input chamber312 can be longitudinally bounded by the input channel 304 and the firstradial layer 322.

In some examples, the treatment units 306 can be configured to filterparticulates out of the exhaust and/or convert pollutant species beforeemitting treated exhaust to atmosphere. In at least one example, thetreatment units 306 can be substantially similar to treatment units 208as described with respect to FIG. 2 . In addition, the treatment units306 can be configured so that a series of treatment unit layers arearranged to treat exhaust from associated power system(s). For example,each radial layer (e.g., each group of two or more treatment unitsdisplayed vertically by FIG. 3 ) can be configured such that theindividual treatment units are sealed to each other along the radialaxis (e.g., sealed together by a structure such as the support lattice210). It should be noted that the treatment units 306 of a radial layer(e.g., treatment units 306 a-306 c of the first radial layer 322) can besealed to other treatment units 306 of the radial layer and/or toresonators 308 that are radially adjacent to the first radial layer 322.For example, the treatment unit 306 c can be sealed to the resonator 308b via a first leg 330 a of the support lattice 210 and the treatmentunit 306 f can be sealed to the resonator 308 d via a second leg 330 bof the support lattice 210. These components can be combined via welds,fasteners, compressive forces applied by the housing 302, and/or otherattaching means (e.g., adhesives, interlocking components, etc.).Further, individual legs of the support lattice 210 can formsubstantially fluid tight seals between the treatment units 306 and/orthe resonators 308. Additionally, the treatment units 306 of each radiallayer can be in fluid communication with an upstream volume (e.g., theinput chamber 312 for the first radial layer 322) immediately upstreamof the radial layer (e.g., the first radial layer 322) and a downstreamvolume (e.g., the first intra-treatment unit volume for the first radiallayer 322 or the output chamber 320 for the last radial layer)immediately downstream of the radial layer (e.g., the first radial layer322). It should be noted that the flow direction arrow of FIG. 3indicates the flow of exhaust through the reduction device 300 fromupstream volumes to downstream volumes. Additionally, it should be notedthat the upstream volume and the downstream volume may referencedifferent volumes for each radial layer. Accordingly, each treatmentunit 306 within a radial layer can receive gaseous species to be treatedfrom a common upstream volume and output treated gaseous species to acommon downstream volume.

In some additional examples, the treatment units 306 can be configuredto occupy various 3D volumes within the reduction device 300. Forexample, the treatment units can be configured to be cuboids, spheres,cylinders, or other 3D shapes that have a cross-sectional area for theexhaust to pass through. Additionally, and based at least on the 3Dshape of the treatment units 306, one or more resonators 308 can bepositioned between the treatment units 306 within available volumebetween treatment units that form due to imperfect nesting of shapes.More specifically, while some shapes, such as cuboids and hexagonalprisms can be configured such that there is minimal available volumebetween individual 3D shapes. Alternatively, or in addition, someshapes, such as cylinders, spheres, and octagonal prisms can beconfigured such that the available volume between the shapes (e.g., acuboid volume is outlined by octagonal prisms that are nested in closeproximity). Accordingly, based on the shape of the treatment units 306,the available volume between the treatment units 306 can be utilized toplace additional resonators within the reduction device 300.

In some further examples, the radial layers of the treatment units 306can be configured to include one or more resonators 308. In particular,the individual treatment units of a radial layer of treatment units 306(e.g., treatment units 306 a-306 c of the first radial layer 322) can bereplaced by one or more resonators 308. For example, the treatment unit306 b of the first radial layer 322 can be replaced with an additionalresonator (not illustrated). Additionally, the additional resonator canbe configured to prevent gaseous species from traversing the firstradial layer 322 via the additional resonator through substantiallyfluid tight seals being formed with the treatment unit 306 a and thetreatment unit 306 c. The substantially fluid tight seals can be formedsimilar to the seals formed by the first leg 330 a and the second leg330 b of the support lattice 210 described above. Alternatively, or inaddition, the treatment units 306 can be associated with a sealing plate334 that is connected to an exhaust channel of the reduction device 300(e.g., exhaust channel 206), one or more treatment units 306 (e.g.,treatment unit 306 c), one or more resonators 308 (e.g., resonator 308b), one or more legs of a support lattice (e.g., first leg 330 a of thesupport lattice), and/or an inner surface of the housing 302 (e.g.,inner surface 202 b). The sealing plate 334 can be configured to form asubstantially fluid tight seal and substantially prohibit the exhaustentering the input chamber 312 from exiting the housing 302 withoutpassing through the treatment units 306. Accordingly, additionalattenuation components can be incorporated in the reduction device 300where the exhaust processing load enables one or more treatment units306 to be removed from one or more radial layers of the reduction device300. In at least one additional example, a radial layer can be replacedby a layer of resonators 308. In particular, a radial layer (e.g., thefirst radial layer 322 or another radial layer within the reductiondevice 300) can be configured such that individual units of thetreatment units 306 within the radial layer are replaced with one ormore resonators 308. Additionally, the one or more resonators that areutilized to replace the one or more treatment units 306 can beconfigured such that exhaust may pass the resonators and continuethrough the reduction device 300. Accordingly, the reduction device 300may include a layer of resonators 308 that are placed upstream of,within, and/or downstream of the radial layers of the treatment units306. For example, an additional resonator can be located in the firstintra-treatment unit volume 314 upstream of the second radial layer 324,in the second intra-treatment unit volume 316 downstream of the secondradial layer 324, at the position of the treatment unit 306 e within thesecond radial layer 324, and/or between the treatment unit 306 d and thetreatment unit 306 e within the second radial layer 324.

In some examples, resonators 308 can be configured based on the audiocharacteristics of the sound output by an associated power system. Inparticular, the audio profile of the sound output by the associatedpower system can be determined based at least on operatingcharacteristics and/or anticipated operating characteristics of thepower system. Additionally, the resonators 308 can be configured in amanner similar to that discussed with reference to FIG. 2 for the firstresonator 212, the second resonator 214, and/or the additionalresonators 218. For example, the power system can be comprised of anumber of cylinders within an engine block, a temperature of the exhaustoutput by the power system, and an RPM of the power system whileoperating. Additionally, the frequency (or frequencies) attenuated bythe resonators 308 can be configured by adjusting the cross-sectionalarea of the resonator neck, the volume of the resonators 308, the massof the resonators 308, and other characteristics of the resonators 308.Accordingly, the resonators 308 can be configured to attenuatefrequencies generated by the power system, identified based at least onthe operating characteristics of the power system (e.g., the number ofcylinders, the exhaust temperature, the RPM of the power system, etc.),by altering the structural characteristics of the resonators 308.

As noted above “tuning” the various resonators of the reduction device300 (and other reduction devices discussed herein), refers to modifyingthe opening, volume, depth, mass, and other variables associated withthe resonators to adjust the frequency and/or range of frequencies thatare attenuated by the resonators. By modifying the internal volume ofthe resonators, the area of the opening, the effective neck length, andother variables, the targeted frequencies of the various resonators canbe tuned to sound wave and frequencies output by the power systemassociated with the reduction device 300. More specifically, whereoperating characteristics and/or a range of operating characteristics isknown, anticipated, or otherwise associated with the power system, theresonators 308 of the reduction device 300 can be modified and/orconfigured to provide attenuation for the associated power system duringoperation at the operating characteristics and/or the range of operatingcharacteristics. Additionally, the type of resonator can be selectedbased on the sound output by the power system as some types ofresonators (e.g., Helmholtz resonators, ¼ wavelength resonators, etc.)can provide greater levels of attenuation, broader ranges of frequenciesattenuated, and/or other tradeoffs that enable optimization of theattenuation provide by the reduction device 300 to the associated powersystem. Further, the attenuation provided by the resonator can beconfigured based on the associated power system at the time ofmanufacturing such that the reduction device is paired with the powersystem or the various resonators can be removed, replaced, and/orreconfigured (e.g., semi-active resonators) by a user that is modifyingthe attenuation provided for the associated power system.

For example, the associated power system can operate at a rated loadthat is associated with a number of active cylinders within the powersystem, a temperature of the exhaust output by the power system, and anRPM of the active cylinders during operation. Based on these operatingcharacteristics, a range of frequencies can be determined forattenuation. The range of frequencies can be utilized to identifyresonator types and resonator characteristics (e.g., opening area,internal volume, etc.) to be utilized in attenuating the range offrequencies produced by the power system. Accordingly, appropriateresonators can be manufactured, configured, obtained, and/or installedin the exterior housing of the reduction device 300. Additionally,should the range of frequencies be modified, a user of the system canremove any resonators that are determined to be ineffective for therange of frequencies for replacement and/or reconfiguration in light ofthe modified range of frequencies through altered internal volumes,effective lengths, cross-sectional areas, and other relevant resonatorparameters.

In some additional examples, placement of the resonators 308 can bedetermined based at least on an attenuation load (e.g., a number ofdecibels that the sound amplitude is to be reduced by), available volumefor resonator placement, and other characteristics of the reductiondevice 300. In particular, for an associated power system, a reductiondevice 300 can be configured based at least on a rate of exhaustprocessing, an attenuation load, and an interior volume of the reductiondevice. The rate of exhaust processing can represent the amount ofexhaust output by the associated power system per unit time and bedetermined based at least on the rated load, the number of cylinders,the operating range, and/or other operating characteristics of theassociated power system. The attenuation load can be determined based atleast on the output decibels of the associated power system (e.g.,determined based at least on the operating characteristics of theassociated power system) and a decibel target that is based at least inpart on the ambient noise level within the facility associated with thepower system. Accordingly, the number of treatment units is determinedbased on the rate of exhaust processing associated with the powersystem. Further, the interior volume of the reduction device 300 can bedetermined based at least in part on the number of treatment unitsdetermined from the rate of exhaust processing. Additionally, theattenuation components are determined for the reduction device 300 basedat least on operating characteristics of the associated power system,the attenuation load, the interior volume of the reduction device 300,cost considerations, and/or other characteristics of the reductiondevice 300 and the associated power system.

In at least one example, the placement of the resonators 308 can bedetermined based at least on an attenuation load determined based atleast on an associated power system and an available volume forresonator placement within the reduction device 300. In particular, theresonators 308 can be configured to occupy a volume of space that isdisposed radially around an exhaust channel and/or a matrix of treatmentunits 306 that are disposed within an exterior housing of the reductiondevice 300. For example, cuboid treatment units can be configured in amatrix that is three treatment units wide, by three treatment unitstall, and four treatment units deep. Additionally, the treatment unitmatrix can be encapsulated within a cylindrical exterior housing suchthat an amount of volume that is not occupied by the treatment unitsexists between exterior surfaces of the treatment unit matrix and theinterior surface of the exterior housing. Accordingly, the availablevolume for resonator placement can be determined based at least on afirst volume 338 between the housing 302 and the treatment units 306 anda second volume 340 between the exterior hull and the treatment units306. It should be noted that the available volume can include the inputchannel 304 upstream of the radial layers and/or the output chamber 320downstream of the radial layers. Further, and based at least on theavailable volume for resonator placement, resonators can be configuredto have resonator characteristics determined to target frequenciesoutput by the associated power system within the operating range of thepower system. Accordingly, sufficient resonators to satisfy theattenuation load across a set of frequencies can be configured to occupythe available volume.

In at least one additional example, the placement of resonators 308 canbe determined to provide an attenuation amount for a range offrequencies associated with the power system. Additionally, and based atleast on the attenuation amount provided by the resonators 308,additional attenuation component(s) can be placed upstream and/ordownstream of the reduction device 300 to attenuate the residualattenuation load (e.g., a subset of the attenuation load that is notsatisfied by the attenuation components within the reduction device). Inparticular, the resonators placed within the reduction device 300 can beplaced in parallel with the treatment units 306 of the reduction device300. Additionally, the additional attenuation component(s) can be placedin series with the reduction device 300 to attenuate the residualattenuation load. However, while the residual attenuation for somesystems may warrant the additional attenuation components, in someadditional applications the residual attenuation may be attenuated viathe incorporation of additional resonators upstream and/or downstream ofthe treatment unit matrix. Accordingly, resonators may be installed inparallel with the treatment units and/or in series with the treatmentunits to attenuate the attenuation load associated with the powersystem.

In some further examples, placement of the resonators 308 can bedetermined based at least on an attenuation load (e.g., a number ofdecibels that the sound amplitude is to be reduced by), the range offrequencies to be attenuated, and other characteristics of the reductiondevice 300. In particular, for an associated power system, theresonators 308 can be tuned such that individual resonators areconfigured to provide more efficient attenuation of specific frequenciesand/or sub-ranges of frequencies. Additionally, the tuning of resonatorscan be accomplished by modifying the cross-sectional area of the openingto the resonator, the internal volume of the resonator, the depth of theresonator, the mass of the resonator, the inclusion of sound attenuatingmaterials within the resonator, and other characteristics of differenttypes of resonators. Accordingly, based on the individual resonatorcharacteristics, the resonators 308 can be placed within the availablevolume of the reduction device 300. More specifically, larger resonatorscan be paired with smaller resonators to more efficiently utilize theavailable volume within the reduction device 300. Further, due tovariations in the cross-sectional area in the opening to individualresonators, the configuration of the treatment units 306 can also bemodified for placement of the resonators 308. In at least one example,the intra-treatment unit length L can be determined based at least on aresonator opening that is exposed to the first intra-treatment unitvolume 314. It should be noted that the intra-treatment unit length Lcan be measured from the downstream face (e.g., downstream face 342) ofa treatment unit (e.g., treatment unit 306 c) to the upstream face(e.g., upstream face 344) of a second treatment unit (e.g., treatmentunit 306 f). Additionally, the intra-treatment unit length L can varyfor different intra-treatment unit volumes. Accordingly, the placementof both treatment units 306 and resonators 308 can be modified withinthe reduction device 300 to provide attenuation for the range offrequencies output by the power system.

In some examples, the placement of resonators 308 can be substantiallyin parallel (e.g., placing individual units in at least a single radialplane that extends from the longitudinal axis of the reduction device300 at least partially within the housing 302 such that at least aportion of treatment unit profiles and resonator profiles overlap on theradial plane) to the placement of the treatment units 306. Inparticular, placing resonators 308 in parallel with the treatment units306 can include placing the resonators 308 radially outward of thetreatment units 306. More specifically, the resonators 308 can be placedat least partially in one or more planes perpendicular to thelongitudinal axis that is shared by the treatment units 306 of one ormore radial layers. For example, the resonators 308 a and 308 b areplaced in parallel with the first radial layer 322 which is comprised oftreatment units 306 a-306 c, the resonators 308 c and 308 d are placedin parallel with the second radial layer 324 comprised of treatmentunits 306 d-306 f, the resonators 308 e and 308 f are placed in parallelwith the third radial layer 326 comprised of treatment units 306 g-306i, and the resonators 308 g and 308 h are placed in parallel with thefourth radial layer 328 comprised of treatment units 306 j-306 l.Accordingly, a single vertical line can be drawn through the treatmentunits of a radial layer that also passes through the resonators that arein parallel with the radial layer. Additionally, the resonators 308placed in parallel with the treatment units 306 can be in fluidcommunication with at least an upstream volume or a downstream volumeassociated with a radial layer (e.g., the input chamber 312 or the firstintra-treatment unit volume 314 downstream of the first radial layer322). Alternatively, or in addition, the resonators 308 can be in fluidcommunication with a volume that located in a radial plane that isupstream or downstream of the treatment units 306, such as the inputchamber 312 and/or the output chamber 320. In at least one additionalembodiment, one or more resonators 308 can be placed radially inward ofthe treatment units 306 of a radial layer. As noted above, a treatmentunit 306 (e.g., treatment unit 306 b, 306 e, 306 g, 306 l, or othertreatment unit 306) can be replaced by one or more additional resonatorssuch that the one or more additional resonators are within the radiallayer (e.g., the first radial layer 322, the second radial layer 324,etc.) and are optionally radially inward of one or more treatment units(e.g., a resonator that replaces treatment unit 306 b is radially inwardof treatment unit 306 a and 306 c).

In some examples, the treatment unit 306 a includes a first surfacefacing the input chamber 312 and configured to receive the exhaust fromthe input chamber 312. Additionally, the treatment unit 306 d includes asecond surface facing the treatment unit 306 a and configured to receiveexhaust from the treatment unit 306 a. Further, attenuation component(e.g., the resonator 308 a or the resonator 308 c) includes a thirdsurface facing the input chamber 312, the third surface being disposedsubstantially coplanar with the first surface of the treatment unit 306a or the second surface of the treatment unit 306 d. It should be notedthat the specific treatment units and specific resonators can refer toany of the treatment units 306 a-306 l and any of the resonators 308a-308 h.

In some additional examples, the treatment unit 306 a includes a firstsurface facing the input chamber 312 and configured to receive theexhaust from the input chamber 312. Additionally, the treatment unit 306d includes a second surface facing the treatment unit 306 a andconfigured to receive exhaust from the treatment unit 306 a. Further,the resonator 308 a includes a third surface facing the input chamber312, the third surface being disposed substantially coplanar with thefirst surface. Additionally, the resonator 308 c includes a fourthsurface facing the resonator 308 a, the fourth surface being disposedsubstantially coplanar with the second surface.

As noted above, the reduction device 300 can be configured to receivethe exhaust at the input chamber 312 of the housing 302, the inputchamber 312 being in fluid communication with the output chamber 320 ofthe housing 302 via an exhaust channel of the housing 302. The exhaustchannel can be an independent structure (e.g., exhaust channel 206)and/or formed via substantially fluid tight seals between the treatmentunits 306, the resonators 308 (e.g., substantially fluid tight seal332), one or more sealing plates 334, one or more legs of the supportlattice (e.g., the first leg 330 a and the second leg 330 b), and thehousing 302. More specifically, the substantially fluid tight seals canbe configured to prohibit the exhaust entering the housing 302 and theinput chamber 312 from bypassing the treatment units 306 before exitingthe housing 302 via the output chamber 320. A substantially fluid tightseal 332 can be formed between the resonators 308 and the housing 302similar to the substantially fluid tight seal formed between the firstleg 330 a and/or the second leg 330 b of the support lattice, thetreatment units 306, and/or the resonators 308. Accordingly, theresonators 308 can attenuate, via placement within the housing 302 andfluid connection to the exhaust channel, a range of frequenciesassociated with the exhaust. Similarly, the treatment units 306 canremove one or more pollutant species from the exhaust as the exhaustpasses through the exhaust channel.

FIG. 4 is a longitudinal cross-section illustration of a reductiondevice that incorporates Helmholtz resonators in parallel with treatmentunits. In some examples, reduction device 400 can share some componentswith the reduction device 300 or include additional components differentfrom the reduction device 300 (not illustrated). In particular, thereduction device 400 includes a housing 302, an input channel 304,treatment units 306, and output channel 310. Additionally, the reductiondevice 400 can include an input chamber 312 that is positionedlongitudinally upstream of the treatment units 306, a firstintra-treatment unit volume 314, a second intra-treatment unit volume316, and a third intra-treatment unit volume 318 (e.g., longitudinallydisposed volumes between two radial layers of treatment units 306 a-306l), and an output chamber 320 that is positioned longitudinallydownstream of the treatment units 306 a-306 l. Further, the reductiondevice 400 can include configured Helmholtz resonators 402, 404, 406,408, 410, and 412. It should be noted that the Helmholtz resonators402-412 are fluidly sealed to prevent throughflow from an upstreamvolume to a downstream volume.

In some examples, a Helmholtz resonator 402 can be configured toattenuate sounds output by a power system associated with the reductiondevice 400. In particular, the Helmholtz resonator 402 can be configuredto extend in the longitudinal direction such that the Helmholtzresonator 402 is configured in parallel with a first radial layer 322, asecond radial layer 324, and third radial layer 326 of the reductiondevice 400. Additionally, the Helmholtz resonator 402 can be configuredto include an opening with cross-sectional area A1 and a length L1 of aneck 402 a associated with the opening of the Helmholtz resonator 402.The cross-sectional area A1 and the length L1 of the neck 402 a can bedetermined based at least in part on a range of frequencies to beattenuated by the Helmholtz resonator 402. Further, the Helmholtzresonator 402 can be configured to be in fluid communication with theinput chamber 312 of the reduction device 400. In at least one example,and as described above, the Helmholtz resonator 402 can be a passiveresonator or a semi-active resonator based at least in part on theoperating characteristics of the associated power system. For example,where the power system is associated with a rated load that the powersystem will commonly operate at, the Helmholtz resonator 402 can beconfigured to attenuate a range of frequencies associated with the ratedload (e.g., statically attenuate the range of frequencies as a passiveresonator). Alternatively, or in addition, where the power system isassociated with an operating range that the power load can fluctuatewithin (e.g., a large machine regulation point, a locomotive notchspeed, or a marine propeller curve, low idle operation, etc.) theHelmholtz resonator 402 can be configured to attenuate a range offrequencies associated with the power system that may change as thepower load fluctuates within the operating range (e.g., the Helmholtzresonator 402 can alter the internal volume of the resonator to modifythe attenuated range of frequencies as a semi-active resonator).

In some examples, a Helmholtz resonator 404 can be configured toattenuate sounds output by a power system associated with the reductiondevice 400. In particular, the Helmholtz resonator 404 can be configuredto extend in the longitudinal direction such that the Helmholtzresonator 404 is configured in parallel with a fourth radial layer 328of the reduction device 400. Additionally, the Helmholtz resonator 404can be configured to include an opening with cross-sectional area A2determined based at least in part on a range of frequencies to beattenuated by the Helmholtz resonator 404. Further, the Helmholtzresonator 404 can be configured to be in fluid communication with theoutput chamber 320 of the reduction device 400 via a neck 404 a. Itshould be noted that the cross-sectional area A2 of the neck 404 a canbe different from the cross-sectional area A1 of the neck 402 a whileretaining the length L1 such that a different range of frequencies areattenuated by the Helmholtz resonator 404 due to the variation in thecross-sectional area A2 of the neck 404 a. In at least one example, theHelmholtz resonator 402 and the Helmholtz resonator 404 can be utilizedto provide attenuation for a first range of frequencies associated withthe Helmholtz resonator 402 and a second range of frequencies associatedwith the Helmholtz resonator 404. In particular, the Helmholtz resonator402 and the Helmholtz resonator 404 can be acoustic cells that utilizeunequal volumes, unequal lengths, and/or other unequal characteristicsto target different ranges of frequencies to attenuate. Accordingly,utilization of individual resonators having different resonatorcharacteristics can broaden the range of frequencies attenuated by thereduction device 400.

In some examples, a Helmholtz resonator 406 can be configured toattenuate sounds output by a power system associated with the reductiondevice 400. In particular, the Helmholtz resonator 406 can be configuredto extend in the longitudinal direction such that the Helmholtzresonator 406 is configured in parallel with the first radial layer 322of the reduction device 400. Additionally, the Helmholtz resonator 40can be configured to include an opening that is associated with a neck406 a that has a length L2 determined based at least in part on a rangeof frequencies to be attenuated by the Helmholtz resonator 406. Itshould be noted that the length L2 of the neck 406 a can be differentfrom the length L1 of the neck 402 a while retaining the cross-sectionalarea A1 such that a different range of frequencies are attenuated by theHelmholtz resonator 406 due to the variation in the effective length theneck 406 a. Further, the Helmholtz resonator 406 can be configured to bein fluid communication with the first intra-treatment unit volume 314 ofthe reduction device 400. In at least one example, the Helmholtzresonator 402 and the Helmholtz resonator 406 can be utilized to provideattenuation for a first range of frequencies associated with theHelmholtz resonator 402 and a third range of frequencies associated withthe Helmholtz resonator 406. In particular, the Helmholtz resonator 402and the Helmholtz resonator 406 can be acoustic cells that utilizeunequal opening volumes, unequal opening lengths, and/or other unequalcharacteristics to target different ranges of frequencies to attenuate.Accordingly, utilization of individual resonators having differentresonator opening characteristics can broaden the range of frequenciesattenuated by the reduction device 400. Further, the resonator openingsmay utilize a pipe and/or neck that extends into the internal volume ofthe Helmholtz resonator for the purpose of tuning the attenuatedfrequencies.

In some examples, a Helmholtz resonator 408 and Helmholtz resonator 410can be configured to attenuate sounds output by a power systemassociated with the reduction device 400. In particular, the Helmholtzresonator 408 can be configured to extend in the longitudinal directionsuch that the Helmholtz resonator 408 is configured in parallel with thesecond radial layer 324 of the reduction device 400 and is in fluidcommunication with both the second intra-treatment unit volume 316 via aneck 408 a and the Helmholtz resonator 410 via a neck 410 a. Similarly,the Helmholtz resonator 410 can be configured to extend in thelongitudinal direction such that the Helmholtz resonator 410 isconfigured in parallel with the third radial layer 326 of the reductiondevice 400, is in fluid communication with the Helmholtz resonator 408via the neck 410 a and is in fluid communication with the secondintra-treatment unit volume 316 via the neck 410 a and the neck 408 a.Additionally, the Helmholtz resonator 408 can be configured to includefirst opening, via the neck 408 a to a second intra-treatment unitvolume 316 and a second opening to the Helmholtz resonator 410, via neck410 a, such that the Helmholtz resonator 410 is in fluid communicationwith the second intra-treatment unit volume via the Helmholtz resonator408. Accordingly, Helmholtz resonators 408 and 410 can be configured asa multi-tuned resonator and/or a nested attenuation component that iscomprised of multiple tuned chambers. It should be noted that whileHelmholtz resonators 408 and 410 are connected longitudinally, in someadditional examples, the Helmholtz resonators can be configured toconnect radially (e.g., Helmholtz resonator 410 is radially outward fromHelmholtz resonator 408), via a combination of radial and longitudinalconnections, or via a hybrid radial/longitudinal connection. Further,the combination of connected chambers can be utilized to broaden therange of attenuated frequencies and/or increase the attenuation providedby the resonators (e.g., at least partially overlapping ranges ofattenuated frequencies).

In some examples, a Helmholtz resonator 412 can be configured toattenuate sounds output by a power system associated with the reductiondevice 400. In particular, the Helmholtz resonator 412 can be configuredto extend in the longitudinal direction such that the Helmholtzresonator 412 is configured in parallel with the fourth radial layer ofthe reduction device 400. Additionally, the Helmholtz resonator 412 canbe configured to include an opening that includes a neck 412 a thatextends into the third intra-treatment unit volume 318 and fluidlyconnects the third intra-treatment unit volume 318 of the reductiondevice 400 with the Helmholtz resonator 412. Accordingly, utilization ofindividual resonators having different resonator opening characteristicscan broaden the range of frequencies attenuated by the reduction device400.

FIG. 5 is a longitudinal cross-section illustration of a reductiondevice that incorporates ¼ wavelength resonators in parallel withtreatment units. In some examples, reduction device 500 can share somecomponents with the reduction device 300 or include additionalcomponents different from the reduction device 300 (not illustrated). Inparticular, the reduction device 500 includes a housing 302, an inputchannel 304, treatment units 306, and output channel 310. Additionally,the reduction device 500 can include an input chamber 312 that ispositioned longitudinally upstream of the treatment units 306, a firstintra-treatment unit volume 314, a second intra-treatment unit volume316, and a third intra-treatment unit volume 318 (e.g., longitudinallydisposed volumes that are between two radial layers of treatment units306 a-306 l), and an output chamber 320 that is positionedlongitudinally downstream of the treatment units 306 a-306 l. Further,the reduction device 500 can include configured ¼ wavelength resonators502, 504, and 506. It should be noted that the ¼ wavelength resonators502-506 are fluidly sealed to prevent throughflow from an upstreamvolume to a downstream volume.

In some examples, a ¼ wavelength resonator 502 can be configured toattenuate sounds output by a power system associated with the reductiondevice 500. In particular, the ¼ wavelength resonator 502 can beconfigured to extend in the longitudinal direction such that the ¼wavelength resonator 502 is configured in parallel with a first radiallayer 322, a second radial layer 324, a third radial layer 326, and afourth radial layer 328 of the reduction device 500. Additionally, the ¼wavelength resonator 502 can be configured to include an opening with afirst cross-sectional area A3 and a first length L3 that are determinedbased at least in part on one or more wavelengths of the sound wavesemitted by an associated power system. The one or more wavelengths areassociated with a range of frequencies to be attenuated by ¼ wavelengthresonator 502 and/or the degree of attenuation to be provided by the ¼wavelength resonator 502. Further, the ¼ wavelength resonator 502 can beconfigured to be in fluid communication with the input chamber 312 ofthe reduction device 500. In at least one example, and as describedabove, the ¼ wavelength resonator 502 can be a passive resonator or asemi-active resonator based at least in part on the operatingcharacteristics of the associated power system. For example, where thepower system is associated with a rated load that the power system willcommonly operate at, the ¼ wavelength resonator 502 can be configured toattenuate a range of frequencies associated with the rated load (e.g.,statically attenuate the range of frequencies as a passive resonator).Alternatively, or in addition, where the power system is associated withan operating range that the power load can fluctuate within, the ¼wavelength resonator 502 can be configured to attenuate a range offrequencies associated with the power system that may change as thepower load fluctuates within the operating range (e.g., the ¼ wavelengthresonator 502 can alter the internal volume of the resonator to modifythe attenuated range of frequencies).

In some examples, a ¼ wavelength resonator 504 can be configured toattenuate sounds output by a power system associated with the reductiondevice 500. In particular, the ¼ wavelength resonator 504 can beconfigured to extend in the longitudinal direction such that the ¼wavelength resonator 504 is configured in parallel with the first radiallayer 322, the second radial layer 324, and the third radial layer 326of the reduction device 500. Additionally, the ¼ wavelength resonator504 can be configured to include an opening with a secondcross-sectional area A4, optionally different from the firstcross-sectional area A3, and a second length that is determined as aneffective length do to the non-linear design of the ¼ wavelengthresonator 504. The effective length of the ¼ wavelength resonator 504can be determined based at least in part on one or more wavelengthsassociated with a range of frequencies output by the associated powersystem. Further, the ¼ wavelength resonator 504 can be configured to bein fluid communication with the input chamber 312 of the reductiondevice 500. In at least one example, the ¼ wavelength resonator 504 canbe configured to include a portion that doubles back over a portion orsubstantially all of the longitudinal length in parallel with the firstradial layer 322, the second radial layer 324, and the third radiallayer 326 of the reduction device 500. In particular, the length of the¼ wavelength resonator 504 can be configured to attenuate additionalfrequencies via an extension of the resonator. As depicted, the ¼wavelength resonator 504 can extend through a fluid seal 508 thatmaintains a substantially fluid tight seal such that an external portion510 of the ¼ wavelength resonator 504 may extend beyond the internalcapacity of the exterior housing 302. It should be noted that due to thebend in the ¼ wavelength resonator 504, the second length is aneffective second length that is different from a linear measurement ofthe ¼ wavelength resonator 504 due to the acoustic impact of the bend.In at least one additional embodiment, the ¼ wavelength resonator canfold back on itself within the housing 302 such the external portion 510of the ¼ wavelength resonator 504 is internal to the exterior housing302 and forms a double layer resonator where the external portion 510 isdisposed radially outward from the treatment units 306 and radiallywithin the housing 302. In particular, where the internal volume of thereduction device 500 provides sufficient space for the ¼ wavelengthresonator 504 to double back, the cross-sectional area of the ¼wavelength resonator 504 can be reduced to enable the placement of theresonator within the housing 302 to extend the effective length of the ¼wavelength resonator.

In some examples, a ¼ wavelength resonator 506 can be configured toattenuate sounds output by a power system associated with the reductiondevice 500. In particular, the ¼ wavelength resonator 506 can beconfigured to extend in the longitudinal direction such that the ¼wavelength resonator 506 is configured in parallel with the fourthradial layer 328 of the reduction device 500. Additionally, the ¼wavelength resonator 506 can be configured to include an opening with athird cross-sectional area A5 and a third length determined based atleast in part on a range of frequencies to be attenuated by the ¼wavelength resonator 506. Further, the ¼ wavelength resonator 506 can beconfigured to be in fluid communication with the output chamber 320 ofthe reduction device 500.

FIG. 6 is a longitudinal cross-section illustration of a reductiondevice that incorporates Helmholtz resonators and ¼ wavelengthresonators in parallel with treatment units. In some examples, reductiondevice 600 can share some components with the reduction device 300 orinclude additional components different from the reduction device 300(not illustrated). In particular, the reduction device 600 includes ahousing 302, an input channel 304, treatment units 306, and outputchannel 310. Additionally, the reduction device 600 can include an inputchamber 312 that is positioned longitudinally upstream of the treatmentunits 306, a first intra-treatment unit volume 314, a secondintra-treatment unit volume 316, and a third intra-treatment unit volume318 (e.g., longitudinally disposed volumes that are between two radiallayers of treatment units 306 a-306 l), and an output chamber 320 thatis positioned longitudinally downstream of the treatment units 306 a-306l. Further, the reduction device 600 can include configured bothHelmholtz resonator 602 and ¼ wavelength resonators 604 and 608. Itshould be noted that the Helmholtz resonator 602 and the ¼ wavelengthresonators 604 and 608 can be fluidly sealed to prevent throughflow froman upstream volume to a downstream volume.

In some examples, a Helmholtz resonator 602 can be configured toattenuate sounds output by a power system associated with the reductiondevice 600. In particular, the Helmholtz resonator 602 can be configuredto extend in the longitudinal direction such that the Helmholtzresonator 602 is configured in parallel with a first radial layer 322, asecond radial layer 324, and a third radial layer 326 of the reductiondevice 600. However, wall 606 of the Helmholtz resonator 602 can beconfigured to adjust the longitudinal length so that the Helmholtzresonator 602 is configured in parallel with at least one of the firstradial layer 322, the second radial layer 324, the third radial layer326, and/or the fourth radial layer 328 of the reduction device 600.Additionally, the longitudinal dimension of the Helmholtz resonator 602can be modified based at least on operating parameters associated withthe flow of exhaust received by the input channel 304. For example, oneor more sensors 612 can be installed in the input channel to detect aflowrate of exhaust, a temperature of exhaust, a pressure amplitude, afrequency associated with pressure variations of the exhaust, and otheroperation characteristics (potentially associated with the power systemitself) to determine resonator parameters for providing sufficientand/or accurate attenuation of sound waves generated by the powersystem.

In some examples, a ¼ wavelength resonator 604 can be configured toattenuate sounds output by a power system associated with the reductiondevice 600. In particular, the ¼ wavelength resonator 604 can beconfigured to extend in the longitudinal direction such that the ¼wavelength resonator 604 is configured in parallel with the fourthradial layer 328 of the reduction device 600. Additionally, the ¼wavelength resonator 604 can be modified by the movements of the wall606, similar to the Helmholtz resonator 602 described above. Forexample, wall 606 of the ¼ wavelength resonator 604 can be configured toadjust the longitudinal length so that the ¼ wavelength resonator 604 isconfigured in parallel with at least one of the first radial layer 322,the second radial layer 324, the third radial layer 326, and/or thefourth radial layer 328 of the reduction device 600.

In some examples, a ¼ wavelength resonator 608 can be configured toattenuate sounds output by a power system associated with the reductiondevice 600. In particular, the ¼ wavelength resonator 608 can beconfigured to extend in the longitudinal direction such that the ¼wavelength resonator 608 is configured in parallel with the first radiallayer 322, the second radial layer 324, the third radial layer 326, andthe fourth radial layer 328 of the reduction device 600. Additionally,the ¼ wavelength resonator 608 can include a dissipative silencer 610comprised of an attenuating material. More specifically, the ¼wavelength resonator 608 can include a material that lines one or moreinterior walls of the ¼ wavelength resonator 608 such that additionalattenuation can be provided by the resonator via the absorption ofvibrations by the attenuating material. Further, the ¼ wavelengthresonator 608 can be configured to be in fluid communication with theinput chamber 312 of the reduction device 600. It should be noted thatwhile the illustration of FIG. 6 indicates that only the ¼ wavelengthresonator 608 includes the attenuating material 610, the dissipativesilencer 610/attenuating material can be installed on interior walls ofthe exterior housing and/or the resonators and on exterior surfaces ofthe exterior housing and/or the resonators. Accordingly, providingadditional attenuation material can enable the reduction device 600 tooffer a greater amount of sound attenuation.

FIG. 7 is a radial cross-section illustration of a reduction device thatincorporates Helmholtz resonators and/or ¼ wavelength resonators inparallel with treatment units. In some examples, reduction device 700can share some components with the reduction device 200 or includeadditional components different from the reduction device 200 (notillustrated). In particular, the reduction device 700 includes a housing202, one or more treatment units 208, a support lattice 210, andattenuation material 216. Additionally, the reduction device 700 caninclude a first Helmholtz resonator 602 with a first opening 704, asecond Helmholtz resonator 706 with a second opening 708 and attenuatingmaterial 710, and a third Helmholtz resonator 712 with a third opening714. It should be noted that the Helmholtz resonators 702, 706, and 712can be fluidly sealed with the housing 202 and the support lattice 210to prevent throughflow from an upstream volume to a downstream volume.

In some examples, a Helmholtz resonator 702 can be configured toattenuate sounds output by a power system associated with the reductiondevice 700. In particular, the Helmholtz resonator 702 can be configuredto form a substantially fluid tight seal with a top surface of thetreatment units 208 and/or a top surface of an exhaust channel (e.g.,exhaust channel 206). Additionally, Helmholtz resonator 702 can beconfigured to form a substantially fluid tight seal with a side surfaceof the treatment units 208 and/or a side surface of the exhaust channelthat is substantially perpendicular to the top surface. It should benoted that the Helmholtz resonator 702 may be configured to form a fluidtight seal with any number of surfaces on the treatment units 208 solong as the flow of exhaust is prevented from bypassing the treatmentunits 208 and passes through the treatment units while travelling froman exhaust source to an emission point where the cleaned exhaust isoutput to atmosphere. It should be noted that the Helmholtz resonator702 may be positioned parallel to any number of radial layers of thereduction device 700. Additionally, the Helmholtz resonator 702 can beconfigured to include the first opening 704 with cross-sectional areadefined by radius R2 that can be determined based at least in part on arange of frequencies to be attenuated by the Helmholtz resonator 702.Further, the Helmholtz resonator 702 can be configured to be in fluidcommunication with the input chamber 312 of the reduction device 700.

In some examples, a Helmholtz resonator 706 can be configured toattenuate sounds output by a power system associated with the reductiondevice 700. In particular, the Helmholtz resonator 706 can be configuredto form a substantially fluid tight seal with a surface of the treatmentunits 208 and/or a surface of an exhaust channel (e.g., exhaust channel206). Additionally, Helmholtz resonator 706 can be configured to form asubstantially fluid tight seal such that the attenuating material710/dissipative silencer does not permit the exhaust to bypass thetreatment units 208. It should be noted that the Helmholtz resonator 706may be configured to form a fluid tight seal on one or more sides of theattenuating material 710 so long as the flow of exhaust is preventedfrom bypassing the treatment units 208 and passes through the treatmentunits while travelling from an exhaust source to an emission point wherethe cleaned exhaust is output to atmosphere. It should be noted that theHelmholtz resonator 706 may be positioned parallel to any number ofradial layers of the reduction device 700. Additionally, the Helmholtzresonator 706 can be configured to include the second opening 708 withcross-sectional area defined by radius R3 and a neck that extends intothe volume of the Helmholtz resonator from an intra-treatment unitvolume or other volume within the housing 202 (not illustrated).Further, the Helmholtz resonator 702 can be configured to be in fluidcommunication with the input chamber 312 of the reduction device 700. Inat least one embodiment, the attenuating material 710 can beincorporated to provide additional attenuation for the reduction device700. In particular, different attenuation methods can be associated withdifferent amounts of attenuation (e.g., the amount that a sound waveamplitude can be reduced by), different frequency ranges, and otherattenuation characteristics. Additionally, the utilization of multipleattenuation methods can enable a more effective solution for attenuatinghigh priority frequencies while maintaining some attenuation for otherfrequencies that may be less intrusive, less commonly output, orotherwise not prioritized. Accordingly, the attenuating material 710 canbe incorporated to improve the attenuation performance of the reductiondevice 700.

In some examples, a Helmholtz resonator 712 can be configured toattenuate sounds output by a power system associated with the reductiondevice 700. In particular, the Helmholtz resonator 712 can be configuredto form a substantially fluid tight seal with a surface of the treatmentunits 208 and/or a surface of an exhaust channel (e.g., exhaust channel206). It should be noted that the Helmholtz resonator 712 may beconfigured to form a fluid tight seal with any number of surfaces on thetreatment units 208 so long as the flow of exhaust is prevented frombypassing the treatment units 208 and passes through the treatment unitswhile travelling from an exhaust source to an emission point where thecleaned exhaust is output to atmosphere. It should be noted that theHelmholtz resonator 702 may be positioned parallel to any number ofradial layers of the reduction device 700. Additionally, the Helmholtzresonator 712 can be configured to include an asymmetric opening withcross-sectional area defined by radius R4 that can be determined basedat least in part on a range of frequencies to be attenuated by theHelmholtz resonator 712. Further, the Helmholtz resonator 702 can beconfigured to be in fluid communication with the input chamber 312 ofthe reduction device 700. In at least some embodiments, the opening tothe Helmholtz resonator can be an asymmetrical opening based at least onavailable space with the reduction device 700, based at least on theposition of other attenuation components within the reduction device700, and/or other structural/acoustic considerations that may indicatethat offsetting the third opening 714 from a central, longitudinalradius of the Helmholtz resonator 712 provides a benefit to thereduction device 700.

FIG. 8 is a longitudinal cross-section illustration of a configurablereduction device that incorporates sound attenuation components inparallel and in series with treatment units. In some examples, theconfigurable reduction device 800 can include a housing 302, an inputchannel 802, an in-series attenuation component 804, a configurableinput chamber 806, treatment units 808, configurable resonators 810a-810 d, an output chamber 812, and an output channel 814.

It should be noted that input channel 802 and output channel 814 can besubstantially similar to the above discussions of input channels andoutput channels.

In some examples, a configurable reduction device 800 can be configuredto incorporate the in-series attenuation component 804 that isassociated with the input channel 802 and/or the output channel 814. Inparticular, there may be scenarios where the configurable resonators 810a-810 d that are positioned in parallel with the treatment units 808 donot satisfy the attenuation threshold for an associated power system.Additionally, the configurable resonators 810 a-810 d can provide anamount of attenuation that reduces the amplitude and/or decibels of thesound waves such that a residual attenuation is to be applied to satisfythe attenuation threshold for the power system. Accordingly, thein-series attenuation component 804 can be installed in series with thetreatment units 808, either upstream (illustrated) or downstream (notillustrated) to accomplish the residual attenuation. It should be notedthat the in-series attenuation component 804 that is in series with thetreatment units 808 would have a smaller attenuation capacity comparedto an independent attenuation component that is configured to satisfythe attenuation threshold without the assistance of the configurableresonators 810 a-810 d.

In some examples, the configurable input chamber 806 can be modifiedbased at least on the flowrate of exhaust generated by an associatedpower system. In particular, the configurable reduction device 800 is asystem that may be modified for utilization with a range of powersystems. More specifically, the internal components of the configurablereduction device 800 can be removed from or inserted into theconfigurable input chamber 806 to treat an anticipated flowrate ofexhaust generated by a power system before the treated exhaust isemitted to atmosphere and/or other output. Accordingly, based at leaston an operating range, individual radial arrays of treatment units 808and the configurable resonators 810 a-810 d can be added or removed fromthe configurable input chamber based on the operational range andcharacteristics of the associated power system. Further, for a highexhaust power system, substantially all of the available configurableinput chamber can be filled with radial arrays of treatment units 808and the configurable resonators 810 a-810 d. Alternatively, or inaddition, the output chamber 812 can be a configurable output chamber812 that radial arrays of treatment units 808 and the configurableresonators 810 a-810 d are added to and removed from based on theoperational characteristics of the associated power system.

FIG. 9 is a longitudinal cross-sectional illustration of a reductiondevice 900 that incorporates sound attenuation components in parallelwith treatment units. In some examples, the reduction device 900 caninclude a housing 902, an input channel 904, an input chamber 906, anoutput chamber 908, an output channel 910, a Helmholtz resonator 912, aresonator opening 914, a ¼ wavelength resonator 916, a wall 918, a ¼wavelength resonator 920, and an acoustically porous wall 922. In someadditional examples, the reduction device 900 can share some componentswith the reduction device 300 or include additional components differentfrom the reduction device 300 (not illustrated). In particular, thereduction device 900 can include treatment units 306 a-306 l, a firstintra-treatment unit volume 314, a second intra-treatment unit volume316, and a third intra-treatment unit volume 318 (e.g., longitudinallydisposed volumes that are between two radial layers of treatment units306 a-306 l), a first radial layer 322, a second radial layer 324, athird radial layer 326, and a fourth radial layer 328. Additionally, theinput chamber 906 is positioned longitudinally upstream of the treatmentunits 306 a-306 l, one or more intra-treatment unit volumes (e.g., afirst intra-treatment unit volume 314 through a third intra-treatmentunit volume 318), and the output chamber 908 that is positionedlongitudinally downstream of the treatment units 306 a-306 l.

In some examples, the input channel 904 can be configured to receiveexhaust output by an associated power system (e.g., power system 100).In particular, the input channel 904 can be fluidly connected to theassociated power system such that exhaust from the power system isdirected through the input channel 904 into the input chamber 906.Alternatively, or in addition, the input channel 904 can be fluidlyconnected to a plurality of associated power systems such that exhaustis collected from the plurality of power systems and provided to thereduction device 900 via the input channel 904. Additionally, the inputchannel 904 can be a pipe, a tube, and/or other substantially hollowportion of the housing 902 that is configured to receive exhaust from anassociated power system, direct the exhaust to the input chamber 906,and has a substantially central input channel axis. Further, the inputchannel 904 can be positioned such that the input channel axis is offsetby a distance D4 from the primary longitudinal axis of the reductiondevice 900. It should be noted that the primary longitudinal axis isdisposed substantially central to the primary body 924 of the reductiondevice 900 that houses the treatment units 306 a-306 l and theresonators (e.g., the Helmholtz resonator 912, the ¼ wavelengthresonator 916, the ¼ wavelength resonator 920, and/or any additionalattenuation components). The distance D4 can be measured from the inputchannel axis to the primary longitudinal axis of the reduction device900. Accordingly, the input channel 904 can be configured to inputexhaust from any position on the upstream portion of the reductiondevice 900. This can include one or more walls of the housing 902 thatare disposed on the upstream portion of the reduction device 900 thatenclose the input chamber 906.

Additionally, the input channel 904 can be fluidly connected to an inputchamber 906 that precedes the treatment units 306 a-306 l, the Helmholtzresonator 912, the ¼ wavelength resonator 916, the ¼ wavelengthresonator 920, and/or any additional attenuation components. Inparticular, the input chamber 906 may be in fluid communication with theHelmholtz resonator 912, the ¼ wavelength resonator 920, any additionalattenuation components, and/or the treatment units 306 a-306 l.Additionally, the Helmholtz resonator 912, the ¼ wavelength resonator920, and/or any additional attenuation components in fluid communicationwith the input chamber 906 can be substantially sealed such that exhaustentering the Helmholtz resonator 912, the ¼ wavelength resonator 920,and/or the additional attenuation components is substantially preventedfrom bypassing the treatment units 306 a-306 l. It should be noted thatthe input chamber 906 is defined by the housing 902, the input channel904, the treatment units 306 a-306 l, the Helmholtz resonator 912, the ¼wavelength resonator 920, and/or any additional resonators such that theexhaust is permitted to enter the input chamber 906 via the inputchannel 904 and exit the input chamber 906 via the first radial layer322 of the treatment units 306.

In some examples, after passing through the treatment units 306 a-306 l,the exhaust enters the output chamber 908. Similar to the input chamber906, the output chamber 908 can be downstream of the treatment units 306a-306 l and is in fluid communication with the output channel 910, thetreatment units 306 a-306 l, the ¼ wavelength resonator 916, and/or anyadditional attenuation components within the housing 902. Additionally,the ¼ wavelength resonator 916 and/or any additional attenuationcomponents in fluid communication with the output chamber 908 can besubstantially sealed such that exhaust entering the ¼ wavelengthresonator 916 and/or the additional attenuation components issubstantially prevented from bypassing the treatment units 306 a-306 l.It should be noted that the output chamber 908 is defined by the housing902, the output channel 910, the treatment units 306 a-306 l, the ¼wavelength resonator 916, and/or any additional resonators such that theexhaust is permitted to enter the output chamber 908 via the fourthradial layer of the treatment units and exit the output chamber 908 viathe output channel 910.

In some examples, the output channel 910 can be configured to outputexhaust received from and treated by the treatment units 306 a-306 l. Inparticular, the output channel 910 can be fluidly connected to thetreatment units 306 a-306 l via the output chamber 908 such that treatedexhaust from the power system is directed from the output chamber 908,through the output channel 910, and output to an external environmentsuch as the atmosphere. Similar to the input channel 904, the outputchannel 910 can be a pipe, a tube, and/or other substantially hollowportion of the housing 902 that is configured to receive the treatedexhaust from the treatment units 306 a-306 l via the output chamber 908and has a substantially central output channel axis. Further, the outputchannel 910 can be positioned such that the output channel axis isoffset by a distance D5 from the primary longitudinal axis of thereduction device 900. It should be noted that the primary longitudinalaxis is disposed substantially central to the primary body 924 of thereduction device 900 that houses the treatment units 306 a-306 l and theresonators (e.g., the Helmholtz resonator 912, the ¼ wavelengthresonator 916, the ¼ wavelength resonator 920, and/or any additionalattenuation components). The distance D5 can be measured from the outputchannel axis to the primary longitudinal axis of the reduction device900. Accordingly, the output channel 910 can be configured to outputexhaust from any position on the downstream portion of the reductiondevice 900. This can include one or more walls of the housing 902 thatare disposed on the downstream portion of the reduction device 900 thatenclose the output chamber 908.

In some examples, the Helmholtz resonator 912 can be configured suchthat it includes one or more acoustically porous walls such that theHelmholtz resonator 912 is configured to provide sound attenuation whilesubstantially preventing the exhaust from bypassing the treatment units306 a-306 l. As noted above, the Helmholtz resonator 912 can beconfigured to attenuate a specific frequency and/or a range offrequencies. In particular, the Helmholtz resonator can be configured toattenuate a range of frequencies (or frequency) defined at least in parton a cross-sectional area of a neck of the Helmholtz resonator 912, thevolume of the Helmholtz resonator 912, and other attributes of theHelmholtz resonator 912 (e.g., mass associated with the resonator, thepressure within the resonator, length of the neck of the resonator,etc.). Accordingly, individual attributes (e.g., the cross-sectionalarea, the internal volume, the mass, etc.) of the Helmholtz resonator912 can be altered to determine the frequencies (or frequency) that isattenuated by the Helmholtz resonator 912. Further, the Helmholtzresonator 912 can include a modifiable volume such that the frequencyand/or range of frequencies attenuated by the Helmholtz resonator 912can be adjusted in situ (e.g., semi-active resonator) or by a userduring configuration of the reduction device 900.

In some additional examples, the Helmholtz resonator 912 can include aresonator opening 914 that includes a wall of the Helmholtz resonator912 that is acoustically porous and enables attenuation to be providedby the Helmholtz resonator 912 via acoustic communication with the inputchamber 906, the output chamber 908, and/or the intra-treatment unitvolumes. In particular, the resonator opening 914 can utilize open spacethat exposes the internal volume of the Helmholtz resonator 912 to theexhaust within the input chamber 906, the output chamber 908 (notillustrated), and/or the intra-treatment unit volumes (e.g., the firstintra-treatment unit volume 314, the second intra-treatment unit volume316, the third intra-treatment unit volume 318, etc.). Alternatively, orin addition, the resonator opening 914 can utilize acoustically porouswall configurations that enable attenuation to be provided by theHelmholtz resonator 912 while substantially preventing and/or partiallyrestricting substantial exhaust flow into and out of the Helmholtzresonator 912. For example, the resonator opening 914 can be a wall ofthe Helmholtz resonator 912 that would otherwise enclose the Helmholtzresonator 912 and includes perforations, micro-perforations, a pluralityof holes, and/or other features that enable sound waves to interact withthe Helmholtz resonator 912 and the Helmholtz resonator 912 to provideattenuation within the reduction device 900. It should be noted that theresonator opening can be configured such that the acoustically porouswall can optionally enable the internal volume of the Helmholtzresonator 912 to be in fluid communication with the exhaust (e.g., theinput chamber 906, the output chamber 908, the intra-treatment unitvolumes, etc.), partially restrict fluid communication with the exhaust,and/or substantially prevent fluid communication with the exhaust whileproviding attenuation. In at least one example, the resonator opening914 can be configured as the open space or the acoustically porous wallwhile the wall 918 of the Helmholtz resonator 912 is configured as anadditional acoustically porous wall. In particular, the resonatoropening 914 and the wall 918 can be configured to substantially restrictexhaust from bypassing the treatment units 306 a-306 l while remainingacoustically porous. It should be noted that while the wall 918 isillustrated as in contact with ¼ wavelength resonator 916, the wall 918can enable acoustic communication with the output chamber 908, aresonator within the housing 902, a resonator outside of the housing902, and/or the intra-treatment unit volumes.

In some examples, the ¼ wavelength resonator 920 can include anacoustically porous wall 922 that enables the ¼ wavelength resonator 920to provide attenuation via acoustic communication with the input chamber906, the output chamber 908, and/or the intra-treatment unit volumes. Inparticular, the acoustically porous wall 922 can enable attenuation tobe provided by the ¼ wavelength resonator 920 while substantiallypreventing and/or partially restricting substantial exhaust flow intoand out of the ¼ wavelength resonator 920. For example, the acousticallyporous wall 920 can be a wall of the ¼ wavelength resonator 920 thatwould otherwise enclose the ¼ wavelength resonator 920 and includesperforations, micro-perforations, a plurality of holes, and/or otherfeatures that enable sound waves to interact with the ¼ wavelengthresonator 920 and the ¼ wavelength resonator 920 to provide attenuationwithin the reduction device 900. It should be noted that the resonatoropening can be configured such that the acoustically porous wall 922 canoptionally enable the internal volume of the ¼ wavelength resonator 920to be in fluid communication with the exhaust (e.g., the input chamber906, the output chamber 908, the intra-treatment unit volumes, etc.),partially restrict fluid communication with the exhaust, and/orsubstantially prevent fluid communication with the exhaust whileproviding attenuation. In at least one example, acoustically porous wall922 can be paired with an additional acoustically porous wall of the ¼wavelength resonator 920. In particular, the acoustically porous wall922 and the additional acoustically porous wall can be configured tosubstantially restrict exhaust from bypassing the treatment units 306a-306 l while remaining acoustically porous to different portions of thereduction device 900. It should be noted that the acoustically porouswall 922 and/or the additional acoustically porous wall can beconfigured such that are in communication with any combination of theinput chamber 906, the output chamber 908, and/or the intra-treatmentunit volumes (including individual intra-treatment unit volumes and/ormultiple-intra-treatment unit volumes depending on the configuration ofthe resonator).

FIG. 10 is a radial cross-sectional illustration of a reduction devicethat incorporates sound attenuation components in parallel with multipleexhaust channels according to further examples of the presentdisclosure. In some examples, reduction device 1000 can share somecomponents with the reduction device 200 or include additionalcomponents different from the reduction device 200 (not illustrated). Inparticular, the reduction device 700 includes a housing 202, an externalsurface 202 a, and/or an internal surface 202 b. Additionally, thereduction device 1000 can include an internal volume 1002, a pluralityof treatment units 1004, a plurality of exhaust channels 1006, aplurality of substantially fluid tight seals 1006 a and 1006 b, a firstresonator 1008, a first resonator opening 1010, a second resonator 1012,a second resonator opening (or a plurality of second resonator openings)1014, and a substantially fluid tight seal 1016. It should be noted thatthe exhaust channels 1006, the first resonator 1008, the secondresonator 1012, and the various substantially fluid tight seals can beconfigured to substantially prevent throughflow from an upstream volumeto a downstream volume and/or substantially prevent the exhaust frombypassing the treatment units 1004.

In some examples, the housing 202 can be radially outward of the othercomponents of the reduction device 1000 and can be configured to providestructural support for the internal components (e.g., the treatmentunits 1004, the exhaust channels 1006, the first resonator 1008, thesecond resonator 1012, etc.). While the housing 202 is depicted as beingcylindrical, the housing 202 may be any three-dimensional (3D) shapethat exhaust from a power system can longitudinally traverse from inputto output. Additionally, the housing 202 can comprise an externalsurface 202 a that is radially outward of an inner surface 202 b,wherein the internal components of the reduction device 1000 can besecured by and/or affixed to the inner surface 202 b of the housing 202.Further, the housing 202 can define the internal volume 1004 for thetreatment of power system exhaust and attenuating sounds from the powersystem.

In some examples, the exhaust channels 1006 extend longitudinally alongand/or within at least a portion of the internal volume 1002 of thehousing 202. In such examples, the exhaust channels 1006 are, at leastin part, in fluid communication with an input of the reduction device1000 and an output of the reduction device 1000. Additionally, thetreatment units 1004 and, optionally, a support lattice associated withthe treatment units 1004 can be disposed within the exhaust channels1006 and supported at least in part by the exhaust channels 1006.Further, the exhaust channels 1006 can be configured such that exhaustentering the reduction device 1000 travels through the exhaust channels1006 before exiting the reduction device 1000. In at least one example,the exhaust channels 1006 form the substantially fluid tight seal 1006 awith the first resonator 1008, the substantially fluid tight seal 1006 bwith the second resonator 1012, and/or an additional substantially fluidtight seal with the inner surface 202 b of the housing 202 (notillustrated) such that the exhaust is prevented from bypassing theexhaust channels 1006. Accordingly, and independent of the specificconfiguration of the exhaust channels 1006, the input and output of thereduction device 200 are in fluid communication with the exhaust channel206 and the exhaust channel 206 can be configured to prevent untreatedexhaust from traversing the reduction device 200 from the input to theoutput.

In some additional examples of the exhaust channels 1006, the input andthe output of the reduction device 1000 are in fluid communication andenable exhaust to traverse the reduction device 1000. For example, theinput and the output of the reduction device 1000 can be disposed onopposite longitudinal ends of the housing 202. Additionally, the inputand the output of the reduction device can be disposed on a firstlongitudinal surface and a second longitudinal surface (e.g., flatsurfaces located on either end of the housing 202 that are perpendicularto the central, longitudinal axis of the reduction device 1000 orconical structures located on either end of the housing 202 that have acentral longitudinal axis that is parallel to the longitudinal axis ofthe reduction device 1000) of the housing 202. Alternatively, or inaddition, the input and the output of the reduction device 1000 can bedisposed on a radial surface (e.g., the exterior surface 202 b of thereduction device 1000) of the reduction device 1000.

In some further embodiments of the exhaust channels 1006, the exhaustchannels 1006 can be configured as a cylindrical wall that encloses thetreatment units 1004, a rectangular wall that includes a first wall, asecond wall, a third wall, and a fourth wall, similar to the exhaustchannel 206, or some other shape that encloses the treatment units 1004.

In some examples, the plurality of treatment units 1004 can be locatedwithin the exhaust channels 1006 to treat exhaust traversing thereduction device 1000. In particular, the treatment units 1004 can bedisposed within the exhaust channels 1006 such that substantially allexhaust that enters the reduction device 1000 passes through at leastone of the treatment units 1004. It should be noted that the exhaustchannels 1006 can be configured to include one or more treatment unitsof the plurality of treatment units 1004 such that the number oftreatment units within the exhaust channels 1006 is substantially thesame for all of the exhaust channels 1006. Additionally, the treatmentunits 1004 within the exhaust channels 1006 can be configured in anynumber of radial layers and longitudinal layers similar to the exhaustchannels of reduction devices 200-900. Further, the treatment units 1004can be supported by a support lattice that secures the treatment units1004 within the exhaust channel 1006. For example, the support latticecan include bars, plates, and/or other structures that are welded,fastened, and/or otherwise joined to form a matrix in which thetreatment units 1004 are disposed. Alternatively, or in addition, thetreatment units 1004 can be secured within the support lattice viacompressive force (e.g., the support lattice 210 is formed such thatpairs of lattice legs are secured to apply compressive force to thetreatment units 1004 and prevent dislocation), fasteners, welds, and/orother components. Further, individual lattice legs of the supportlattice can form a substantially fluid tight seal between individualtreatment units and/or the exhaust channel 1006. Accordingly, thetreatment units 1004 can be placed within the exhaust channels 1006 toconvert and/or capture pollutant species within the exhaust such thatgaseous species exiting the reduction device 1000 can be output toatmosphere and substantially prevent untreated exhaust from bypassingthe treatment units 1004.

In some examples, sound attenuation devices and/or components can beinstalled within the housing 202 and outside of the exhaust channels1006 such that internal volume 1002 of the reduction device 1000 thatwould typically remain empty around the exhaust channels 1006 can beutilized to assist with sound attenuation. In particular, the firstresonator 1008 and the second resonator 1012 can be selected fromvarious resonators that are configured to attenuate sound generated by apower system associated with the reduction device 1000 (e.g., powersystem 100). For example, the first resonator 1008 and the secondresonator 1012 can be selected from Helmholtz resonators, ¼ wavelengthresonators, and/or other resonators that can target a sound frequency ora range of sound frequencies. Additionally, the Helmholtz resonators,the ¼ wavelength resonators, and/or the other resonators can beconfigured as passive resonators (e.g., resonators that attenuate a setrange of frequencies) or semi-active resonators (e.g., resonators thatattenuate a range of frequencies that is determined by a modifiablevolume within the resonator). In at least one embodiment, the reductiondevice 1000 can also include an active resonator that generates anopposite phase sound wave that attenuates the soundwaves generated bythe power system. For example, where a sound wave traversing thereduction device has a trough (e.g., low pressure zone) the activeresonator can generate a pressure peak and where the sound wave has apeak the active resonator can generate a trough such that the overallpressure exiting the reduction device 1000 is at a constant pressure.Accordingly, the first resonator 1008 and the second resonator 1012 canbe selected from various resonator types and configurations to attenuatesound from the associated power system.

In some additional examples, the first resonator 1008 can be selectedfrom a Helmholtz resonator, a ¼ wavelength resonator, or another type ofresonator to attenuate sounds within the reduction device 1000. Inparticular, the first resonator 1008 can be configured to occupy aportion of the internal volume 1002 between the housing 202 and theexhaust channels 1006 and/or between individual exhaust channels of theplurality of exhaust channels 1006. Additionally, the first resonator1008 can be configured to form the substantially fluid tight seal withthe housing 202 and the substantially fluid tight seal 1006 a with theexhaust channels 1006 such that exhaust entering the reduction device1000 is substantially prevented from bypassing the treatment units 1004via the first resonator 1008. Further, the first resonator 1008 can beexposed to the input of the reduction device 1000, the output of thereduction device 1000, or to the intra-treatment unit volumes betweendifferent radial layers of the treatment units 1004 (not illustrated byFIG. 2 ). Accordingly, the first resonator 1008 can be configured suchthat the gas within the first resonator 1008 is substantially similar tothe gas within the portion of the reduction device 1000 that the firstresonator 1008 is exposed to. More specifically, the first resonator1008 can encompass a volume of gas that can enter and exit the firstresonator 1008 via the first resonator opening 1010 (e.g., an openingfor the first resonator corresponding to resonator opening 220 of theadditional resonators 218). As discussed by FIG. 4 , the first resonator1008 (and other resonators associated with the reduction device 1000)can be configured to be in fluid communication with a portion of thereduction device 1000 and substantially isolated from other portions ofthe reduction device 1000 to substantially prevent and/or restrictexhaust from bypassing the treatment units 1004. For example, the firstresonator 1008 can be in fluid communication with the input chamber ofthe reduction device 1000 and fluidly isolated from the output chamberof the reduction device 1000 such that exhaust that enters the firstresonator 1008 from the input chamber exits the first resonator backinto the input chamber before traversing the treatment units 1004 andthe exhaust channels 1006 to the output chamber.

Similarly, the second resonator 1012 can be selected from a Helmholtzresonator, a ¼ wavelength resonator, or another type of resonator toattenuate sounds within the reduction device 1000. In particular, thesecond resonator 1012 can be configured to occupy a portion of thevolume between the exhaust channels 1006. Additionally, the secondresonator 1012 can be configured to form the substantially fluid tightseal 1006 b in combination with the exhaust channels 1006, similar tothe first resonator 1008, such that exhaust entering the reductiondevice 1000 is prevented from bypassing the treatment units 1004 via theresonators. As illustrated by FIG. 10 , the second resonator 1012 can beconfigured such that the second resonator openings 1014 (e.g., openingsfor a Helmholtz resonator) are exposed to the intra-treatment unitvolumes within the exhaust channels 1006. Further, the second resonator1012 can be exposed to substantially the same intra-treatment unitvolume within each of the exhaust channels 1006. For example, the secondopenings 1014 can be configured to expose the second resonator 1012 tothe second intra-treatment unit volume between a second radial layer anda third radial layer of treatment units within each of the exhaustchannels 1006 such that exhaust that enters the second resonator 1012can exit from a first exhaust channel and enter a second exhaust channeland be treated by a number of treatment units that remains substantiallyconstant regardless of whether the exhaust moves between exhaustchannels. Alternatively, or in addition, the second resonator openings1014 may be associated with a single resonator for each of the exhaustchannels such that the second resonator 1012 is subdivided intoindividual resonators that are associated with the individual exhaustchannels. Additionally, there may be some embodiments where the secondresonator openings 1014 are connected to different intra-treatment unitvolumes within the exhaust chambers 1006 and are configured such thatthe throughflow exhaust that bypasses one or more of the treatment units1004 is below a bypass threshold. Accordingly, the first resonator 1008,the second resonator 1012, and/or any additional resonators can providesound attenuation via exposure to various portions of the reductiondevice 1000. In at least one example, the second resonator openings 1014can be configured to share a radius R5 that defines the cross-sectionalarea of the second resonator openings 1014 and partially defines thefrequency and/or the range of frequencies attenuated by the secondresonator 1012. In at least one additional example, the second resonatoropenings 1014 can be configured to be associated with various radii thatdefine the cross-sectional areas of individual openings of the secondresonator openings 1014 and partially define the frequency and/or therange of frequencies attenuated by the second resonator 1012.

In some examples, the substantially fluid tight seal 1016 can be formedbetween a wall of the first resonator 1008, the second resonator 1012,and/or one or more of the exhaust channels 1006 to substantially preventthe exhaust from bypassing the treatment units 1004.

FIG. 11 is a longitudinal cross-sectional illustration of a reductiondevice 1100 that incorporates sound attenuation components in parallelwith treatment units and includes an elbow that changes the direction ofthe longitudinal axis of the reduction device. In some examples, thereduction device 1100 can share some components with the reductiondevice 300 or include additional components different from the reductiondevice 300 (not illustrated). In particular, the reduction device 1100can include treatment units 306 a-306 l, a first intra-treatment unitvolume 314, a second intra-treatment unit volume 316, and a thirdintra-treatment unit volume 318 (e.g., longitudinally disposed volumesthat are between two radial layers of treatment units 306 a-306 l), afirst radial layer 322, a second radial layer 324, a third radial layer326, and a fourth radial layer 328. Additionally, the reduction device1100 can include a housing 1102, an input channel 1104, an input chamber1106, an output chamber 1108, an output channel 1110, a housing elbow1112, a Helmholtz resonator 1114, a ¼ wavelength resonator 1116, a ¼wavelength resonator 1118, one or more additional treatment units 1120a-1120 d, a fifth radial layer 1122, a sixth radial layer 1124, aHelmholtz resonator 1126, and a fourth intra-treatment unit volume 1128.Further, the input chamber 1106 is positioned longitudinally upstream ofthe treatment units 306 a-306 l, one or more intra-treatment unitvolumes (e.g., a first intra-treatment unit volume 314 through a thirdintra-treatment unit volume 318), and the output chamber 1108 that ispositioned longitudinally downstream of the one or more additionaltreatment units 1120 a-1120 d.

In some examples, the input channel 1104 can be configured to receiveexhaust output by an associated power system (e.g., power system 100)for the reduction device 1100. In particular, the input channel 1104 canbe a pipe, a tube, and/or other substantially hollow portion of thehousing 1102 that is configured to receive exhaust from an associatedpower system, direct the exhaust to the input chamber 1106, and has asubstantially central input channel axis. It should be noted that theprimary longitudinal axis is disposed substantially central to housing1102 of the reduction device 1100 and the input channel axis is disposedsubstantially central to the input channel 1104 such that the primarylongitudinal axis and the input channel axis can be parallel,perpendicular, and/or otherwise aligned to intersect. Accordingly, theinput channel 1104 can be configured to input exhaust from any positionon the upstream portion of the reduction device 1100. This can includeone or more walls of the housing 1102 that are disposed on the upstreamportion of the reduction device 1100 that enclose the input chamber1106.

Additionally, the input channel 1104 can be fluidly connected to aninput chamber 1106 that precedes the treatment units 306 a-306 l, theHelmholtz resonator 1114, the ¼ wavelength resonator 1116, the ¼wavelength resonator 1118, the additional treatment units 1120 a-1120 d,the Helmholtz resonator 1126, and/or any additional attenuationcomponents within the housing 1102. In particular, the input chamber1106 may be in fluid communication with the Helmholtz resonator 1114,the ¼ wavelength resonator 1118, any additional attenuation components,and/or the treatment units 306 a-306 l. Additionally, the Helmholtzresonator 1114, the ¼ wavelength resonator 1118, and/or any additionalattenuation components in fluid communication with the input chamber1106 can be substantially sealed such that exhaust entering theHelmholtz resonator 1114, the ¼ wavelength resonator 1118, and/or theadditional attenuation components is substantially prevented frombypassing the treatment units 306 a-306 l. In at least one example, theHelmholtz resonator 1114, the ¼ wavelength resonator 1118, and/or anyadditional attenuation components can be configured to extend from thefirst portion 1130 of the housing 1102 through the housing elbow 1112and into the second portion 1132 of the housing 1102. Accordingly, theHelmholtz resonator 1114, the ¼ wavelength resonator 1118, and/or anyadditional attenuation components can be configured to prevent theexhaust from bypassing the additional treatment units 1120 a-1120 dand/or the treatment units 306 a-306 l. It should be noted that theinput chamber 1106 is defined by the housing 1102, the input channel1104, the treatment units 306 a-306 l, the Helmholtz resonator 1114, the¼ wavelength resonator 1118, and/or any additional resonators such thatthe exhaust is permitted to enter the input chamber 1106 via the inputchannel 1104 and exit the input chamber 1106 via the first radial layer322 of the treatment units 306.

In some examples, after passing through the treatment units 306 a-306 land the additional treatment units 1120 a-1120 d, the exhaust enters theoutput chamber 1108. Similar to the input chamber 1106, the outputchamber 1108 can be downstream of the treatment units 306 a-306 l,downstream of the additional treatment units 1120 a-1120 d, and in fluidcommunication with the output channel 1110, the treatment units 306a-306 l, the additional treatment units 1120 a-1120 d, the Helmholtzresonator 1126, and/or any additional attenuation components within thehousing 1102. Additionally, the Helmholtz resonator 1126 and/or anyadditional attenuation components in fluid communication with the outputchamber 1108 can be substantially sealed such that exhaust entering theHelmholtz resonators 1126 and/or the additional attenuation componentsis substantially prevented from bypassing the additional treatment units1120 a-1120 d. It should be noted that the output chamber 1108 isdefined by the housing 1102, the output channel 1110, the treatmentunits 306 a-306 l, the Helmholtz resonator 1126, and/or any additionalresonators such that the exhaust is permitted to enter the outputchamber 1108 via the sixth radial layer 1124 of the treatment units andexit the output chamber 1108 via the output channel 1110.

In some examples, the output channel 1110 can be configured to outputexhaust received from and treated by the treatment units 306 a-306 l andthe additional treatment units 1120 a-1120 d. In particular, the outputchannel 1110 can be fluidly connected to the additional treatment units1120 a-1120 d via the output chamber 1108 such that treated exhaust fromthe power system is directed from the output chamber 1108, through theoutput channel 1110, and output to an external environment such as theatmosphere. Similar to the input channel 1104, the output channel 1110can be a pipe, a tube, and/or other substantially hollow portion of thehousing 1102 that is configured to receive the treated exhaust from theadditional treatment units 1120 a-1120 d via the output chamber 1108 andhas a substantially central output channel axis. Further, the outputchannel 1110 can be positioned such that the output channel axis isoffset from the primary longitudinal axis of the reduction device 1100.It should be noted that the primary longitudinal axis is disposedsubstantially central to the second portion 1132 of the housing 1102.Accordingly, the output channel 1110 can be configured to output exhaustfrom any position on the downstream portion of the reduction device1100. This can include one or more walls of the housing 1102 that aredisposed on the downstream portion of the reduction device 1100 thatenclose the output chamber 1108.

In some examples, the housing 1102 can include the housing elbow 1112such that the first portion 1130 of the housing 1102 and the secondportion 1132 of the housing 1102 are associated with non-parallelcentral axis. It should be noted that the central longitudinal axis isdefined by the central axis of the first portion 1130 and the centralaxis of the second portion 1132 within the respective portion of thehousing 1102. Additionally, while the housing 1102 is shown to includethe single housing elbow 1112 of approximately 45 degrees, the housing1102 can include any number of elbows having a variety of degrees (e.g.,a 90 degree elbow, a 180 degree elbow, a 120 degree elbow, etc.)Accordingly, the housing may include the housing elbow 1112 such thatindividual treatment units and resonators are located relative to oneanother in parallel or in series based on the central longitudinal axisfor the first portion 1130 and the second portion 1132 of the housing1102. Additionally, it should be noted that longitudinal progressionfrom upstream components (e.g., treatment units 306 a-306 l, resonators1114, 1116, and 118, etc.) to downstream components (e.g., additionaltreatment units 1120 a-1120 d, Helmholtz resonator 1126, etc.) iscontinued through the housing elbow 1112.

In some examples, and independent of position within the first portion1130 or the second portion 1132 of the housing 1102, the Helmholtzresonator 1114, the ¼ wavelength resonator 116, the ¼ wavelengthresonator 118, and/or the Helmholtz resonator 1126 can be configured ina manner similar to that discussed by FIGS. 1-10 . Similarly, theaddition treatment units 1120 a-1120 d, the fifth radial layer 1122, thesixth radial layer 1124, and the fifth intra-treatment volume 1128 canbe configured similar to the first intra-treatment unit volume 314, thesecond intra-treatment unit volume 316, the third intra-treatment unitvolume 318, first radial layer 322, the second radial layer 324, thethird radial layer 326, and the fourth radial layer 328. It should benoted that while the fourth intra-treatment unit volume 1126 may beconfigured similar to the other intra-treatment unit volumes, the fourthintra-treatment unit volume 1126 can be configured to include additionalvolume, treatment units, and/or resonators that occupy the excess volumecaused by the housing elbow 1112. More specifically, as there is avariable longitudinal length at the boundary between the first portion1130 and the second portion 1132 of the housing 1102, the fourthintra-treatment unit volume 1126 may be configured to incorporateadditional components that are shaped to fit within the transitionbetween the first portion 1130 and the second portion 1132.

INDUSTRIAL APPLICABILITY

The present disclosure describes systems and methods for soundattenuation. The example systems and methods described herein can beused with reduction systems for internal combustion-type motors, and thedisclosed systems are configured to target specific frequencies of noisecontent. An exhaust treatment component is comprised of an exteriorhousing that defines an input channel that receives exhaust from anassociated power source, an output channel downstream of the inputchannel, an internal volume, and a longitudinal axis that extendsthrough the internal volume. The internal volume includes an exhaustchannel that contains one or more treatment units for capturingpollutants and/or converting pollutant species to emission species (e.g.pollutant species are to be reduced by the treatment units by conversioninto the emission species that can be vented to atmosphere) and directsexhaust from the input channel to the output channel. The treatmentunits are disposed within the exhaust channel along the longitudinalaxis, optionally in radial layers containing multiple treatment units.Additionally, the internal volume includes attenuation components thatare disposed radially outward of the treatment units and are fluidlyconnected to the exhaust channel to attenuate a range of frequencies.The attenuation components can form substantially fluid tight sealsthat, while providing attenuation, the attenuation components preventexhaust from bypassing the treatment units within the exhaust channel.Similarly, the exhaust channel prohibits exhaust entering the inputchannel from exiting the housing without passing through the treatmentunits. Accordingly, excess volume within the housing of the reductionsystem can be occupied by attenuation components that are disposed inthe same radial planes as the treatment units. Placement of theattenuation components within the excess volume enables attenuation tobe provided without the expense of an additional devices specialized forattenuating the sound waves produced by an operating gen-set.

According to embodiments of the present disclosure, the devicesdescribed herein reduce the amplitude of sound waves by a determinednumber of decibels such that a target noise threshold is satisfied bythe sound output by a gen-set across a wide spectrum of frequencies.Additionally, the incorporation of attenuating apparatuses into theavailable volume between the external housing and reduction catalyststakes advantage of unused volume and reduces or eliminates the need foradditional attenuation apparatuses that are independent of the reductiondevice. Moreover, embodiments described herein can minimize costassociated with manufacturing the apparatuses by combining soundattenuation components with the reduction device to simplify the overallsystem, reduce the footprint of the system within facilities, andpotentially eliminate the need for an additional system that reducesoverall system complexity.

While aspects of the present disclosure have been particularly shown anddescribed with reference to the embodiments above, it will be understoodby those skilled in the art that various additional embodiments may becontemplated by the modification of the disclosed machines, systems andmethods without departing from the spirit and scope of what isdisclosed. Such embodiments should be understood to fall within thescope of the present disclosure as determined based upon the claims andany equivalents thereof.

The invention claimed is:
 1. A reduction device, comprising: a housingdefining: an input chamber configured to receive exhaust from a powersource, an output chamber downstream of the input chamber, an exhaustchannel disposed between the input chamber and the output chamber, theexhaust channel configured to direct the exhaust from the input chamberto the output chamber, and a longitudinal axis extending substantiallycentrally through the housing; a treatment unit disposed in the exhaustchannel and along the longitudinal axis, the treatment unit including afirst surface facing the input chamber, the first surface beingconfigured to receive the exhaust from the input chamber, the treatmentunit being configured to at least partly remove pollutant species fromthe exhaust as the exhaust passes through the exhaust channel; and anattenuation component disposed in the housing and radially outward ofthe treatment unit, wherein: an inlet of the attenuation component isformed by a second surface of the attenuation component downstream ofthe input chamber and substantially coplanar with the first surface, theinput chamber directs the exhaust received from the power sourceunimpeded to the inlet, the attenuation component is fluidly connectedto the exhaust channel, and is configured to attenuate a range offrequencies corresponding to operation of the power source at a ratedload, and the exhaust channel prohibits exhaust entering the inputchamber from exiting the housing without passing through the treatmentunit.
 2. The reduction device of claim 1, wherein: the input chambercomprises an open internal volume of the housing formed by a radiallyoutermost wall of the housing, the open internal volume extending from afirst internal surface of the radially outermost wall to a secondinternal surface of the radially outermost wall facing the firstinternal surface.
 3. The reduction device of claim 1, wherein thetreatment unit further comprises: a treatment unit housing including: afirst wall, a second wall substantially parallel to the first wall, athird wall, and a fourth wall substantially parallel to the third wall,the first wall and the second wall being connected to the third wall andthe fourth wall at substantially right angles; and a substrate disposedwithin the treatment unit housing, the substrate formed from one of ametallic material and a ceramic material, and being configured to removeparticulates from the exhaust as the exhaust passes through thetreatment unit.
 4. The reduction device of claim 3, wherein: thetreatment unit housing is connected to and disposed within the exhaustchannel; and the exhaust channel is configured to direct the exhaustfrom the input chamber to the output chamber via the treatment unithousing.
 5. The reduction device of claim 1, wherein: the attenuationcomponent comprises a first attenuation component fluidly connected to afirst portion of the exhaust channel upstream of the treatment unit; andthe reduction device further includes a second attenuation componentseparate from the first attenuation component, the second attenuationcomponent being fluidly connected to a second portion of the exhaustchannel downstream of the treatment unit.
 6. The reduction device ofclaim 5, further comprising a sealing plate connected to the exhaustchannel and to an inner surface of the housing, the sealing plateprohibiting the exhaust entering the input chamber from exiting thehousing without passing through the treatment unit.
 7. The reductiondevice of claim 1, wherein the rated load is associated with a steadystate operation of the power source, and wherein the steady stateoperation of the power source is defined by: a substantially constantrotations per minute (RPM) of the power source, a substantially constantpower output of the power source, and a substantially constanttemperature of the flow of exhaust.
 8. A method, comprising: receivingexhaust at an input chamber of a housing, the input chamber being influid communication with an output chamber of the housing via an exhaustchannel of the housing; attenuating, with an attenuation componentdisposed within the housing and fluidly connected to the exhaustchannel, a range of frequencies associated with the exhaust as theexhaust passes through the exhaust channel; removing, with at least oneof a first treatment unit and a second treatment unit, a pollutantspecies from the exhaust as the exhaust passes through the exhaustchannel, the first treatment unit being disposed within the exhaustchannel and including a first surface facing the input chamber, thefirst surface receiving the exhaust from the input chamber, the secondtreatment unit being disposed within the exhaust channel downstream of,and spaced from, the first treatment unit, and the attenuation componentbeing disposed radially outward of the first treatment unit and thesecond treatment unit, wherein an inlet of the attenuation component isformed by a second surface of the attenuation component downstream ofthe input chamber and substantially coplanar with the first surface;directing, by the input chamber, the received exhaust unimpeded to theinlet; and directing the exhaust to exit the housing via the outputchamber, the exhaust channel prohibiting the exhaust from exiting thehousing via the output chamber without passing through the at least oneof the first treatment unit and the second treatment unit.
 9. The methodof claim 8, wherein: the second treatment unit includes a third surfacefacing the first treatment unit and configured to receive exhaust fromthe first treatment unit; and the input chamber comprises an openinternal volume of the housing substantially surrounding the inlet ofthe attenuation component.
 10. The method of claim 8, wherein theattenuation component comprises a first attenuation component, themethod further comprising attenuating, with a second attenuationcomponent disposed within the housing and fluidly connected to theexhaust channel, a subset of the range of frequencies, the secondattenuation component being disposed radially outward of the secondtreatment unit.
 11. The method of claim 10, wherein: the secondtreatment unit includes a third surface facing the first treatment unitand configured to receive exhaust from the first treatment unit; and thesecond attenuation component includes a fourth surface facing the firstattenuation component, the fourth surface being disposed substantiallycoplanar with the third surface.
 12. The method of claim 8, wherein afirst substantially fluid tight seal is formed between an inner surfaceof the housing and the attenuation component, and a second substantiallyfluid tight seal is formed between the exhaust channel and theattenuation component, the first and second substantially fluid tightseals prohibiting the exhaust from exiting the housing via the outputchamber without passing through the at least one of the first treatmentunit and the second treatment unit.
 13. The method of claim 8, whereinthe attenuation component comprises one of a Helmholtz resonator and ¼wavelength resonator, and the first treatment unit comprises a substrateformed from one of a metallic material and a ceramic material, thesubstrate being coated with a reduction catalyst.
 14. The method ofclaim 8, wherein the housing comprises a substantially cylindricalhousing, and the exhaust channel comprises a first wall connected to andextending substantially perpendicular to a second wall, a third wallconnected to and extending substantially perpendicular to the secondwall, and a fourth wall connected to and extending substantiallyperpendicular to the third wall and the first wall, the exhaust channelbeing supported, at least in part, by an inner surface of the housing,and the first and second treatment units being supported by a supportlattice connected to at least one of the first wall, the second wall,the third wall, and the fourth wall.
 15. A system, comprising: a powersource configured to emit exhaust; and a reduction device fluidlyconnected to the power source and configured to receive the exhaust, thereduction device comprising: a housing defining an input chamber, anoutput chamber downstream of the input chamber, and a longitudinal axis,an exhaust channel fluidly connecting the input chamber with the outputchamber, the longitudinal axis of the housing extending substantiallycentrally through the exhaust channel, a plurality of treatment unitsdisposed within the exhaust channel, the plurality of treatment unitsbeing configured to remove pollutant species from the exhaust as theexhaust passes through the exhaust channel; a plurality of attenuationcomponents disposed within the housing and fluidly connected to theexhaust channel, the plurality of attenuation components being:configured to attenuate a range of frequencies associated with theexhaust passing through the exhaust channel, and corresponding tooperation of the power source at a rated power load, and disposedradially outward of the plurality of treatment units; and a supportlattice connected to at least one wall of the exhaust channel andsupporting the plurality of treatment units within the exhaust channel,wherein: the reduction device is configured such that the exhaustreceived from the power source is prohibited from exiting the housingwithout passing through at least one treatment unit of the plurality oftreatment units, a first treatment unit of the plurality of treatmentunits includes a first surface facing the input chamber, the firstsurface being configured to receive the exhaust from the input chamber,a first attenuation component of the plurality of attenuation componentsincludes an inlet formed by a second surface of the first attenuationcomponent, the second surface being downstream of the input chamber andsubstantially coplanar with the first surface, and the input chamberdirects the exhaust received from the power source unimpeded to theinlet.
 16. The system of claim 15, wherein the reduction device furtherincludes attenuating material disposed within the housing and radiallyoutward of the exhaust channel.
 17. The system of claim 15, wherein: theinput chamber comprises an open internal volume of the housing formed bya radially outermost wall of the housing, the open internal volumeextends from a first internal surface of the radially outermost wall toa second internal surface of the radially outermost wall facing thefirst internal surface, and the open internal volume substantiallysurrounds the inlet of the first attenuation component.
 18. The systemof claim 15, wherein the first treatment unit is disposed along thelongitudinal axis, the plurality of treatment units further comprising asecond treatment unit disposed along the longitudinal axis and spacedfrom the first treatment unit.
 19. The system of claim 18, wherein: thefirst surface defines a first plane extending substantiallyperpendicular to the longitudinal axis; the second treatment unitincludes a third surface facing the output chamber, the third surfacedefining a second plane extending substantially perpendicular to thelongitudinal axis; and at least one attenuation component of theplurality of attenuation components is disposed, at least in part, at alocation, within the housing and external to the exhaust channel,between the first plane and the second plane.
 20. The system of claim18, wherein at least one attenuation component of the plurality ofattenuation components is fluidly isolated from a portion of the exhaustchannel extending from the first treatment unit to the second treatmentunit.